M-rrrv  rn  TUC 


7- 


V,  ct^c^t^uJLac 


THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 


PRESENTED  BY 

PROF.  CHARLES  A.  KOFOID  AND 
MRS.  PRUDENCE  W.  KOFOID 


CHEMICAL  PATHOLOGY 


BEING  A  DISCUSSION  OF  GENERAL  PATH- 
OLOGY  FROM  THE  STANDPOINT  OF 
THE  CHEMICAL  PROCESSES  INVOLVED 


BY 


H.  GIDEON  WELLS,  Ph.D.,  M.D. 

ASSISTANT   PROFESSOR  OF   PATHOLOGY   IN   THE   UNIVERSITY   OF   CHICAGO 
AND   IN   RUSH    MEDICAL   COLLEGE,   CHICAGO 


PHILADELPHIA  AND  LONDON 

W.    B.    SAUNDERS    COMPANY 

1907 


ftfl 


Copyright,  1907,  by  W.   B.  Saunders  Company 


PRESS    OF 

W.   B.  SAUNDERS    COMPANY 
PHILADELPHIA 


TO 

5Hefttoen 


THIS  BOOK  IS  RESPECTFULLY  DEDICATED,    AS  A 

SLIGHT  TOKEN  OF  THE  GRATITUDE  AND 

ESTEEM   OF    HIS    PUPIL 


PREFACE 


DURING  the  past  score  of  years  the  subject  of  biological  chem- 
istry has  attracted  the  attention  and  labors  of  a  constantly  increasing 
number  of  investigators,  many  of  whom  have,  for  one  reason  or 
another,  been  interested  in  pathological  conditions.  Sometimes  the 
physiologist  has  sought  for  light  on  his  problems  in  the  evidence 
afforded  by  related  pathological  conditions.  Frequently  clinicians 
have  studied  the  metabolic  changes  and  the  composition  of  the 
products  of  disease  processes.  Relatively  seldom,  unfortunately, 
has  the  pathologist  attacked  his  problems  by  chemical  methods. 
From  the  above  and  other  sources  have  come  scattered  fragments 
of  information  concerning  the  chemical  changes  that  occur  in  patho- 
logical phenomena.  Only  when  bearing  upon  conditions  such  as 
gout  and  diabetes,  which  concern  alike  the  physiologist,  the  clinician, 
and  the  pathologist,  have  the  fragments  been  moulded  together  into 
a  homogeneous  whole.  For  the  most  part  they  still  remain  isolated, 
uncorrelated,  frequently  unconfirmed  items  of  information,  scattered 
through  medical,  chemical,  physiological,  and  physical  literature. 

It  has  been  the  aim  of  the  writer  to  collect  these  scattered  frag- 
ments as  completely  as  possible,  and  to  use  them  as  a  basis  for  a 
consideration  of  General  Pathology  from  the  standpoint  of  the  chem- 
ical processes  which  occur  in  pathological  conditions.  Owing  to  the 
diffusely  scattered  condition  of  the  literature  on  which  this  work  is 
based,  it  cannot  be  claimed  that  all  of  the  many  contributions  from 
which  useful  information  might  be  obtained  have  been  noticed  ;  but 
it  is  hoped  that  a  sufficiently  thorough  collection  of  material  has 
been  made  to  afford  a  fair  basis  for  a  consideration  of  "  Chemical 
Pathology."  The  time  seems  ripe  for  an  effort  of  this  nature. 
Within  the  past  few  years  great  and  encouraging  advances  have 
been  made  in  biological  chemistry,  which  in  many  instances  seem 
to  throw  light  upon  pathological  processes.  In  medicine,  the  use 
of  chemical  methods  in  the  study  of  clinical  manifestations  has 
become  more  general,  and  has  yielded  valuable  information.  Path- 
ologists  have  come  to  feel  that  the  opportunities  for  the  acquire- 

7 


8  PREFACE 

ment  of  knowledge  by  means  of  morphological  studies  have  become 
reduced  to  a  minimum,  while  the  fields  of  pathological  physiology 
and  chemistry  lie  still  almost  unexplored.  The  development  of 
research  upon  the  subject  of  natural  and  acquired  immunity  has 
presented  innumerable  problems,  all  of  which  are  essentially  chem- 
ical. And  perhaps  most  important  of  all  is  the  general  awakening 
of  an  appreciation  of  the  importance  of  physiological  chemistry  to 
medical  science,  which  has  led  to  the  introduction  of  laboratory 
courses  on  this  subject  in  every  medical  school  worthy  of  the  name. 

A  book  on  Chemical  Pathology  should,  therefore,  seek  to  supply 
information  to  a  varied  group  of  readers.  It  should  furnish  col- 
lateral reading  to  the  student  who  for  the  first  time  goes  over  the 
subject  of  General  Pathology,  which  his  text-books  usually  consider 
chiefly  from  the  morphological  standpoint.  It  should  exploit  to  the 
graduate  in  medicine  the  advances  that  are  being  made  along  lines 
that  are  of  fundamental  importance  to  clinical  medicine.  It  should 
serve  for  the  investigator  in  biological  chemistry  or  in  pathology  as 
a  source  of  information  concerning  the  ground  upon  which  the  two 
subjects  overlap — the  "  Grenzgebiete "  of  Pathology  and  Physio- 
logical Chemistry.  And,  above  all,  it  should  afford  a  guide  to  the 
sources  of  our  knowledge  of  these  subjects,  since  nothing  but  direct 
familiarity  with  the  original  reports  of  the  investigators  themselves 
can  give  the  student  an  impersonal  view  of  the  actual  status  of  the 
questions  under  consideration.  On  account  of  this  multiplicity  of 
the  objects  in  view,  it  has  often  been  necessary  to  consider  certain 
topics  from  more  than  one  standpoint ;  which  explains,  perhaps, 
certain  apparent  irregularities  in  the  style  and  manner  of  treatment. 

It  has  been  assumed  that  the  reader  has  at  least  an  elementary 
knowledge  of  organic  and  physiological  chemistry.  For  the  benefit 
of  those  whose  studies  in  these  subjects  date  back  some  years,  it  has 
seemed  advisable  to  include  in  an  introductory  chapter  an  epitome 
of  the  more  modern  views  concerning  the  chemistry  of  the  proteid 
molecule,  the  composition  of  the  animal  cell,  and  the  principles  of 
physical  chemistry,  in  as  far  as  they  apply  to  biological  problems. 
The  general  consideration  of  "  Enzymes  "  in  Chapter  II  is  written 
with  a  similar  object.  In  discussing  these  fundamental  topics  it  has 
seemed  advisable  to  omit  detailed  references  to  the  numerous  origi- 
nal sources, — these  may  be  found  quoted  in  the  special  text-books 
cited  in  the  foot-notes ;  but  in  presenting  the  more  distinctly  patho- 
logical topics  the  attempt  has  been  made  to  render  all  the  important 


PREFACE  9 

literature  available  to  the  reader  and  investigator.  To  econo- 
mize space,  a  complete  bibliography  has  not  been  inserted  when 
this  exists  already  collected  in  some  readily  accessible  review  or 
original  article ;  hence  the  references  cited  in  the  foot-notes  will 
generally  be  found  to  include  only  the  more  recent  publications. 
These  references  have  been  so  selected,  however,  that  they  will  be 
found  to  furnish  bibliographical  matter  sufficient  to  lead  the  inves- 
tigator to  all  the  important  literature  on  the  topics  covered  in  this 
book.  As  to  those  subjects  (such  as  gout,  diabetes,  and  gastro- 
intestinal putrefaction)  which,  because  of  their  great  practical  clin- 
ical interest,  have  already  been  discussed  in  available  monographs 
at  greater  length  than  the  scope  of  this  work  would  permit,  it  has 
seemed  appropriate  merely  to  summarize  the  most  recent  views  and 
advances,  referring  the  reader  to  the  special  treatises  for  the  general 
and  historical  discussions. 

It  is  with  the  greatest  pleasure  that  I  acknowledge  my  indebted- 
ness to  many  colleagues  in  the  University  of  Chicago,  who  have 
kindly  read  the  sections  of  my  manuscript  that  touch  upon  their 
own  special  fields,  and  whose  criticism  and  advice  have  been  of  the 
greatest  assistance  ;  their  number  alone  prevents  my  thanking  them 
by  name.  Most  particularly,  however,  must  I  express  my  debt  to 
my  former  instructor,  Professor  Lafayette  B.  Mendel,  of  Yale  Uni- 
versity, whose  kindly  criticism  and  suggestions  have  been  of  ines- 
timable value.  For  constant  assistance  in  the  preparation  of  the 
manuscript,  and  for  the  revision  of  the  bibliography,  I  am  indebted 
to  my  wife. 

H.  G.  W. 

CHICAGO,  January,  1907. 


CONTENTS 


CHAPTER  I 

PAGE 

Introduction 17 

The  Chemistry  and  Physics  of  the  Cell 17 

Chemistry  of  the  Essential  Cell  Constituents      19 

Chemistry  of  the  Proteid  Molecule 19 

The  Physical  Chemistry  of  the  Cell  and  its  Constituents  .  30 
The  Structure  of  the  Cell  in  Relation  to  Its  Chemistry 

and  Physics 52 

CHAPTER  II 

Enzymes 61 

The  Nature  of  Enzymes  and  Their  Action 62 

Toxicity  of  Enzymes 71 

The  Intracellular  Enzymes 75 

Oxidizing  Enzymes 75 

Lipase 82 

CHAPTER  III 

Enzymes  (Continued) 85 

Intracellular  Proteases 85 

Autolysis 86 

CHAPTER  IV 

The  Chemistry  of  Bacteria  and  Their  Products 104 

Structure  and  Physical  Properties 104 

Chemical  Composition 106 

Bacterial  Enzymes 109 

Poisonous  Bacterial  Products 115 

Bacterial  Pigments 127 

CHAPTER  V 

Chemistry  of  the  Animal  Parasites 129 

11 


12  CONTENTS 

CHAPTER  VI  PAGE 

Chemistry  of  Immunity  Against  Bacteria  and  Their  Prod- 
ucts, and  the  Reactions  of  Agglutination  and  Precipita- 
tion   136 

Toxins  and  Antitoxins 137 

Immunity  Against  Bacterial  Cells 143 

Agglutinins  and  Agglutination 148 

Precipitins 152 

CHAPTER  VII 

Chemical  Means  of  Defense  Against  Poisons  of  Known  Com- 
position   157 

Inorganic  Poisons 159 

Organic  Poisons 160 

CHAPTER  VIII 

Phytotoxins  and  Zootoxins 166 

Phytotoxius 166 

Zootoxins 170 

CHAPTER  IX 

Hemolysis  and  Serum  Cytotoxins 187 

Hemolysis  or  Erythrocytolysis 188 

Immune  Cytotoxins  in  General 202 

CHAPTER  X 

Inflammation 207 

Ameboid  Motion  and  Phagocytosis 208 

Theories  of  Chemotaxis  and  Phagocytosis 218 

Artificial  Imitations  of  Ameboid  Motion 220 

Suppuration,  and  the  Chemistry  of  Pus 229 

Chemistry  of  Sputum 233 

Proliferation  and  Regeneration 235 

CHAPTER  XI 

Disturbances  of  Circulation  and  Diseases  of  the  Blood  ....  238 

Composition  of  the  Blood 238 

Alkalinity  of  the  Blood 240 

Hemorrhage 242 

Hemophilia 245 

Anemia  and  the  Specific  Anemias 248 

Hyperemia 260 

Thrombosis,  and  the  Coagulation  of  Blood 262 

Embolism 272 

Infarction  .  .  273 


CONTENTS  13 

CHAPTEK  XII  PAGE 

Edema 276 

Formation  of  Lymph 277 

Absorption  of  Lymph 283 

Causes  of  Edema 284 

Special  Varieties  of  Edema 291 

Composition  of  Edematous  Fluids 295 

Chemistry  of  Pneumothorax 305 

CHAPTER  XIII 

Retrogressive  Processes 307 

Necrosis 307 

Necrosis,  Varieties  of 318 

Gangrene 325 

Rigor  Mortis 326 

Cloudy  Swelling 329 

CHAPTER  XIV 

Retrogressive  Processes  (Continued) 332 

Fatty  Metamorphosis 332 

Processes  Related  to  Fatty  Metamorphosis 342 

Amyloid  Degeneration 347 

Hyaline  Degeneration 353 

Colloid  Degeneration 354 

Mucoid  Degeneration 356 

Glycogen  in  Pathological  Processes 358 

CHAPTER  XV 

Calcification,  Concretions,  and  Incrustations 364 

Calcification 364 

Osteomalacia  and  Rickets 371 

Concretions 375 

Pneumonokoniosis 392 

CHAPTER  XVI 

Pathological  Pigmentation 393 

Melanotic  Pigmentation 393 

Lipochromes 399 

Hematogenous  Pigmentation 400 

Icterus » 405 

CHAPTER  XVII 

The  Chemistry  of  Tumors 411 

Chemistry  of  Tumors  in  General 412 

Chemistry  of  Benign  Tumors 420 

Chemistry  of  Malignant  Tumors 425 


14  CONTENTS 

CHAPTER  XVIII  PAGE 

Pathological  Conditions  Due  to,  or  Associated  with,  Abnormal- 
ities in  Metabolism,  Including  Auto-intoxication    .    .    .  431 

Uremia 433 

Eclampsia      439 

Acute  Yellow  Atrophy  of  the  Liver 443 

Acid  Intoxication      451 

Fatigue 459 

Poisons  Produced  in  Superficial  Burns    .    .    .,  •  ,•    •    •    .461 

CHAPTER  XIX 

Gastro-intestinal  Auto-intoxication  and  Related  Metabolic  Dis- 
turbances  464 

Constituents  of  the  Digestive  Fluids 465 

Products  of  Normal  Digestion 466 

Products  of  Putrefaction  and  Fermentation 468 

Derivatives  of  the  Aromatic  Radicals 469 

Alkaptonuria 475 

Cystinuria 478 

CHAPTER  XX 

Chemical  Pathology  of  the  Ductless  Glands 483 

Diseases  of  the  Thyroid 483 

Acromegaly  and  the  Hypophysis    . 496 

The  Adrenals  and  Addison's  Disease .  498 

CHAPTER  XXI 

Uric-acid  Metabolism  and  Gout 503 

Chemistry  of  Uric  Acid 503 

Gout  .    ." ....  511 

CHAPTER  XXII 

Diabetes 516 

Experimental  Glycosuria 516 

Pancreatic  Glycosuria 525 

Human  Diabetes 531 

Diabetes  Insipidus 536 

INDEX  .  537 


CHEMICAL    PATHOLOGY 


WELLS 


CHEMICAL  PATHOLOGY 


CHAPTER  I 
INTRODUCTION 
THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL 

SIXCE  Virchow  founded  modern  pathology  the  unit  of  all 
anatomical  considerations  of  disease  has  been  the  cell,  and  in 
physiology  the  same  unit  has  been  found  equally  useful.  When 
either  physiological  or  pathological  processes  are  studied  from 
a  chemical  standpoint,  the  cell  is  still  found  occupying  nearly  as 
fundamental  a  position,  for  we  can  seldom  go  back  to  molecules 
and  atoms  in  investigating  biological  problems.  Although  we 
know  that  within  each  cell  are  many  different  chemical  sub- 
stances, and  that  numerous  different  enzymes  and  other  agencies 
are  exerting  their  influence  upon  them,  yet  we  find  that  the 
reactions  are  all  profoundly  affected  by  the  environment  in  which 
they  occur,  and  it  is  the  structure  of  the  cell  that  determines 
the  environment  of  its  chemical  constituents.  All  chemical 
reactions  are  modified  by  physical  influences,  and  an  enzyme 
may  have  quite  a  different  effect  upon  a  substance  when  it  acts 
in  a  test-tube  from  what  it  will  have  when  in  a  living  cell, 
whose  structure  permits  the  diffusion  of  one  substance  while 
preventing  that  of  another,  and  where  countless  other  substances 
and  enzymes  may  participate  in  the  changes.  The  cell  is  the 
structural  unit  of  the  living  organism,  and  as  by  its  physical 
properties  it  modifies  chemical  processes,  so  it  becomes  prac- 
tically the  unit  in  physiological  and  pathological  chemistry. 
All  consideration  of  the  chemistry  of  disease  must  thus  refer  back 
to  the  chemistry  and  physics  of  the  normal  cell,  and  on  this 
account  a  brief  resume"  of  these  subjects  may  serve  as  a  fitting 
introduction  to  the  strictly  pathological  matters  to  follow.1 

1  Of  necessity,  only  so  much  of  the  very  extensive  literature  on  cell  structure 
and  cell  chemistry  can  be  considered  as  will  have  direct  bearing  upon  the 
subject  matter  to  follow,  referring  the  reader  for  more  detailed  information 
to  such  works  as  Wilson's  "  The  Cell  in  Development  and  Inheritance "  ; 
Mann's  "  Physiological  Histology  "  ;  Hammarsten's  "  Physiological  Chemistry  "  ; 
Abderhalden's  "  Lehrbuch  der  physiologischen  Chemie  "  ;  Gurwitsch's  "  Mor- 
phologic und  Biologic  der  Zelle";  Hober's  "  Physikalische  Chemie  der 
Zelle  und  der  Gewebe  "  ;  Hamburger's  "  Osmotischer  Druck  und  lonenlehre  "  ; 
Loeb's  "  Dynamics  of  Living  Matter  ",  for  general  discussion,  and  to  the  most 
important  monographs  for  treatment  of  special  points. 

2  17 


18  INTRODUCTION 

As  applied  to  the  animal  tissues,  the  term  "  cell "  is  entirely 
a  misnomer,  for  it  describes  accurately  only  such  forms  of 
"  cells  "  as  are  found  in  plants,  in  which  the  prominent  feature 
is  the  limiting  wall,  forming  a  cell  to  enclose  a  fluid  content. 
In  most  instances  the  "  cell "  answers  better  to  the  definition, 
"  a  mass  of  protoplasm ";  but  usage  makes  language,  and  no 
possible  confusion  can  arise  from  the  prevailing,  universal  use 
of  the  original  term,  except,  perhaps,  that  the  term  is  prone  to 
carry  with  it  the  thought  of  the  walls  of  the  cell  being  much 
more  prominent  than  they  really  are.  This  is  not  so  unfortunate 
a  result,  perhaps,  for,  as  we  shall  see  later,  the  limiting  surfaces 
of  the  cell,  even  when  too  thin  to  be  readily  demonstrable, 
play  a  much  more  important  part  in  cell  chemistry  than  their 
appearance  indicates. 

The  morphological  division  of  the  cell  into  cell  wall,  cytoplasm, 
nucleus,  and  nucleolus  can  hardly  be  followed  out  chemically, 
for  if  we  surmount  to  some  extent  the  difficulties  in  the  way  of 
studying  the  different  portions  separately,  we  find  that  the  dif- 
ferences between  them  are  rather  quantitative  than  qualitative. 
And,  furthermore,  however  different  the  cells  of  one  organ  or 
tissue  may  appear  from  those  of  another  organ  or  tissue  under 
the  microscope,  when  analyzed  by  the  chemical  methods  at 
present  at  our  disposal  we  find  the  differences  very  slight  indeed. 
Certain  substances  are  found  in  every  living  cell,  and  in  quan- 
tities usually  not  greatly  dissimilar ;  hence  they  are  assumed  to 
be  the  most  important  constituents  of  protoplasm,  and  are 
sometimes  called  the  primary  constituents  of  the  cell.  Many 
other  secondary  constituents  may  also  be  present,  some  of 
which  are  so  nearly  universal  that  we  are  not  sure  but  that 
better  methods  would  show  them  to  be  constant  and  primary 
cell  components  ;  such  are  fat  and  glycogen.  Others  are  charac- 
teristics of  certain  cells,  such  as  melanin  and  keratin,  or  specific 
products  of  cell  metabolism,  such  as  mucin  and  the  specific 
enzymes.  The  great  histological  and  chemical  differences  ex- 
isting between  different  tissues  depend  often  on  these  secondary 
products,  as  in  fat  tissue  and  squamous  epithelium ;  or  upon 
the  intercellular  substance,  as  with  connective  tissue,  cartilage, 
bone,  etc.,  which  may  be  looked  upon  as  products  of  cell  activity. 

Protoplasm,  as  the  term  is  generally  used,  includes  the 
various  primary  constituents  with  the  fluids  permeating  or  dis- 
solving them,  but  does  not  include  the  more  conspicuous 
secondary  constituents,  such  as  fat  droplets,  pigment  granules, 
etc.,  nor  the  cell  membrane  when  such  exists.  Evidently  it  is 
a  very  indefinite  term,  to  be  avoided  as  much  as  possible,  par- 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL        19 

ticularly  because  of  the  confusion  as  to  whether  it  includes  the 
nucleus  or  not,  different  authors  differing  in  this  respect  in  their 
usage  of  the  word. 

CHEMISTRY  OF  THE  ESSENTIAL  CELL  CONSTITUENTS 

To  enumerate  the  primary  or  essential  constituents  of  the  cell 
absolutely  is  not  possible,  for  the  rapid  advances  in  chemistry 
may  alter  all  classifications  without  warning,  but  practically  they 
may  be  grouped  under  the  headings  of  proteids,  lipoids,  salts, 
and  water,  and  no  attempt  will  be  made  to  give  here  more  than 
the  most  essential  features  concerning  each. 

PROTEIDS  ! 

In  the  last  few  years  we  have  obtained  something  approach- 
ing a  scientific  understanding  of  the  chemical  nature  of  this 
great  group  of  the  most  highly  complex  bodies  known  to  chem- 
istry, although  we  are  still  far  from  a  position  where  it  can 
be  positively  said  just  how  the  various  components  of  the 
molecule  are  united,  or  in  exactly  what  proportion  ;  and  we  are 
still  farther,  perhaps,  from  the  point  of  synthesizing  a  full-fledged 
proteid  molecule.  But  it  is  believed  by  many  chemists  that  the 
problems  regarding  the  underlying  principles  of  the  formation 
and  structure  of  the  giant  proteid  molecule  are  nearing  solution. 
Our  information  has  been  obtained  almost  exclusively  through 
studies  of  the  products  obtained  by  splitting  up  the  proteids, 
for  as  yet  little  has  been  accomplished  through  synthesis.  The 
names  of  Kossel  and  Emil  Fischer  are  most  prominently 
connected  with  this  work.  Proteids  can  be  decomposed  by  the 
action  upon  them  of  acids  or  alkalies  in  various  concentrations, 
by  superheated  steam,  by  digestive  ferments,  and  by  bacteria. 
The  products  obtained  in  these  different  ways  are  not  all  the 
same,  for  some  substances  may  be  formed  by  oxidation,  reduction, 
decomposition,  combination,  or  condensation  of  the  various 
products  of  simple  cleavage,  and  it  is  necessary  to  distinguish 
between  the  primary  cleavage  products  (those  which  exist  as 
radicals  within  the  molecule)  and  the  secondary  products  (those 
not  existing  preformed  in  the  molecule  but  formed  by  transfor- 
mation of  the  primary  products).  This  can  usually  be  done, 
and  it  is  found  that  so  far  as  the  primary  products  are  concerned, 
it  makes  little  difference  which  method  of  cleavage  (or  %- 
drolysis,  since  in  the  splitting,  water  is  combined  with  the  organic 
substances)  is  used. 

1  For  the  complete  literature  of  this  subject  see  Mann's  "  Chemistry  of  the 
Proteids,  "  New  York,  1906. 


20  INTRODUCTION 

At  first  the  proteids  split  up  into  compounds  still  possessing 
many  of  the  features  of  the  typical  proteid  molecule,  such  as 
albumoses  and  peptones,  and  these  bodies  are  then  further  resolved 
into  simple  substances,  which  are  not  aggregates  of  several 
smaller  molecules  as  are  the  proteids,  and  which  can  be  obtained 
in  pure  crystalline  form.  No  matter  which  method  is  used  we 
find  the  process  going  through  these  stages,  and,  as  before 
mentioned,  the  primary  crystalline  products  obtained  are  prac- 
tically the  same  quantitatively  as  well  as  qualitatively.  Some 
methods,  e.  g.,  bacterial  decomposition,  however,  lead  in  the 
end  to  more  profound  or  different  decomposition  of  the  cleavage 
products  into  secondary  substances.  The  similarity  of  the 
results  obtained  in  these  different  ways  indicates  that  there  are 
definite  lines  of  cleavage  in  the  proteid  molecule  along  which 
separation  takes  place,  independent  of  the  nature  of  the  agency 
at  work,  and  that  the  substances  obtained  represent,  as  the 
Germans  figuratively  say,  the  "  building  stones  "  of  the  entire 
molecule.  A  large  number  of  such  elementary  constituents 
have  already  been  isolated  and  identified  with  certainty, 
although  there  is  no  doubt  that  there  remain  others  still  undis- 
covered. The  best  known  of  these  are  the  following : 

1.  Glycocoll,  ClC-COOH. 

2.  Alanin,  CH3  -  CH^- COOH. 

3.  Amino-valerianic  acid,        f^u\      ^TT    Xtr     rv^rr 

^O±i3)2  =  C±l — v>xl  —  LAXJU. 

4.  Leucin,        ( CH3)  2  =  CH— CH2— CH  —  COOH. 

These  four  bodies  are  all  simple  amino-acids  of  the  fatty  acid 
series,  and  represent  typical  members  of  the  series  as  far  as  the 
hexane  derivatives. 

5.  Aspartic  acid,       HOOC— CH2— CH—  COOH. 

6.  Glutaminic  acid,       HOOC— CH2— CH2— CH  —  COOH. 

These  two  dibasic  acids  are  also  closely  related  to  the  mon- 
atomic  acids,  as  can  be  seen  from  their  structural  formula?. 

7.  Phenyl-alanin,       /         J>-CH2-CH  —  COOH. 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL         21 


8.  Tyrosin,       HO<  >—CH2-CH  —  COOH. 


/NH2 

.       /CH,-CH-COOH. 
9.  Tryptophan,1 


These  three  substances  represent  the  aromatic  constituents  of 
the  proteid  molecule,  and  differ  from  the  simpler  amino-acids 
merely  in  the  presence  of  the  benzene  ring. 

10.  a-pyrrolidin  carboxylic  acid  (prolin), 
H2C      CH  — COOH. 


1  1  .  Oxy-a-pyrrolidin  carboxylic  acid  2  (oxy-prolin), 
H2C—  CH2 

(?)  HO  —  HC      CH  —  COOH. 
NH 

Both  of  these  substances  lie  under  the  suspicion  of  being 
formed  from  some  other  amino-acid  through  re-arrangement 
within  the  molecule  during  the  process  of  cleavage,  but  this 
idea  has  not  been  positively  established,  and  they  are  among 
the  most  constantly  obtained  of  the  cleavage  products. 


12    Serin  /OH/NH, 

—        — 


CH  —  CH  —  COOH. 

This  substance,  together  with  oxy-0-pyrrolidin  carboxylic 
acid,  is  important  as  being  an  oxy-acid,  which  brings  the  proteid 
molecule  into  close  relation  with  the  carbohydrates.  Amino- 
compounds  even  more  closely  related  to  the  carbohydrates  have 
occasionally  been  isolated  (glucosamin)  and  it  is  possible  that 
they  are  frequently  present  in  proteids. 

NH, 
_  ^  _  ^  _  ^  _  CH  _  COOH> 

NH  NH 

"1   A          A  *      *  II  /       "^^2 

1D'        H2N  —  C  —  NH  —  CH2—  CH2  —  CH2—  CH  —  COOH. 

1  The  exact  structure  of  tiyptophan  has  not  been  finally  determined  ;  the 
above  formula,  that  of  El  linger,  seems  to  be  most  probably  the  correct  one. 

2  The  position  of  the  OH  group  in   oxy-prolin  has   not  yet  been  finally 
determined 


/2  /, 

13.  Lysm, 


22  INTRODUCTION 

15.   Histidin/  ~ 


/* 
-CH  —  C 


—  C—  CH2-CH  —  COOH. 

The  members  of  this  important  group  differ  from  all  the 
bodies  previously  described  in  having  more  than  one  NH2 
radical.  Kossel  termed  them  the  hexone  bases  because  each  has 
six  carbon  atoms,  but  the  more  descriptive  term,  diamino-acids, 
is  now  more  generally  used.  On  account  of  their  wide  occurrence, 
(no  proteid  has  yet  been  found  free  from  arginin)  their  prominent 
part  in  the  formation  of  the  so-called  "  simplest  proteids  "  (the 
protamins),  they  have  been  held  by  some  to  form  the  real 
nucleus  of  the  proteid  molecule. 

/NH2 
CH2  —  CH-COOH 

I 
16.  Cystin,  5 


CH2-CH  —  COH. 

Apparently  the  sulphur  in  the  proteids  exists  chiefly,  if  not 
solely,  in  this  form.  Cystin  is  closely  related  to  the  sulphur-  free 
amino-acids,  as  can  be  seen  by  comparing  the  following  formula?  : 


CH3  —  CH  —  COOH  (  Alanin); 

/OH   XNH2 

CH2  —  CH  —  COOH  (Serin); 

/SH    /NH, 

CH2  —  CH  —  COOH  (Cystein); 


CH2  —  CH  —  COOH 


I  /NH2 

CH2  —  CH  —  COOH  (Cystin). 

If  we  consider  the  composition  of  these  substances,  we  notice 
that  there  is  one  important  point  that  they  all  have  in  common  : 
each  one  is  an  acid,  which  has  a  NH2  group  substituted  for  a 
hydrogen  atom  on  the  carbon  nearest  the  add  radical  (the  a- 

1  The  structure  of  histidin  is  not  finally  determined.     The  formula  given, 
that  of  Pauly,  is  believed  to  be  correct. 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL        23 

position).  It  makes  no  difference  what  the  rest  of  the  radicals 
are,  whether  they  are  simple  chains  (leucin),  or  members  of  the 
cyclic  or  aromatic  series  (tyrosin),  or  sulphur-containing  bodies 
(cystin),  without  exception  this  relation  of  a  NH2  group  to  an 
acid  radical  is  constant,  as  in  this  formula  : 

NH2 
E  — CH  — COOH. 

Through  this  arrangement  every  one  of  the  constituents  of 
the  proteid  molecule  is  provided  with  a  group  with  a  strong 
basic  character  and  a  group  with  a  strong  acid  character,  and 
hence  it  is  possible  for  them  to  unite  with  one  another  in  indefi- 
nite numbers,  and,  because  of  the  great  variety  of  individuals, 
in  practically  an  infinite  number  of  combinations.  It  is  believed 
that  it  is  in  just  this  way  that  the  proteid  molecule  is  built  up. 
By  artificially  uniting  various  cleavage  products  Emil  Fischer 
has  succeeded  in  producing  large  molecules  made  up  of  several 
amino-acid  radicals  (called  by  him  "  polypeptids ") l  which 
show  some  of  the  characteristics  of  the  peptones,  and  this  is  the 
nearest  that  investigators  have  yet  come  to  synthesizing  a  proteid 
molecule.  The  union  is  accomplished  by  the  splitting  off  of 
water,  corresponding  to  the  addition  of  water  that  occurs  when  the 
proteid  molecule  undergoes  cleavage.  It  may  be  illustrated  by 
showing  the  formation  of  the  simplest  polypeptid,  glycylglycin. 

/NH2^0 XNH2     ^O 

CH2 — c  -  Jon  +  H]HN  —  CH2 — COOH  =  cn2 c — HN — cn2  --  COOH  +  H2o. 

(glycocoll)  (glycocoll)  (glycylglycin) 

For  these  reasons  it  is  believed  that  the  proteid  molecule 
consists  of  great  numbers  of  amino-acid  groups,  combined  with 
one  another  through  their  basic  and  acid  radicals,  and  that  the 
various  proteids  are  different  from  one  another  because  they 
contain  different  numbers  or  varieties  of  amino-acids.  For 
example,  the  globin  of  hemoglobin  yields  no  glycocoll  on  hy- 
drolysis, while  gelatin  yields  16.5  per  cent.  On  the  other  hand, 
gelatin  is  free  from  tyrosin.  Some  of  the  protamins  (proteids 
obtained  chiefly  from  spermatozoa)  yield  as  high  as  58  to  84 
per  cent,  of  arginin,  while  the  simpler  amino-acids  with  but 
one  N  (mono-amino-acids)  are  scanty,  and  most  varieties  are 
lacking. 

It  will  be  noticed  that  when  two  amino-acids  unite,  as  seen 
in  the  formation  of  glycylglycin,  an  acid  radical  and  a  basic 
radical  are  still  left  free.  In  this  may  be  seen  the  explanation 

1  Reviewed  by  Fischer,  in  Ber.  deut.  Chem.  Gesell.,  1906  (39),  530. 


24  INTRODUCTION 

of  the  peculiar  amphoteric  nature  of  proteids.  As  long  as  these 
two  groups  are  free  the  proteids  can  combine  with  either  acids 
or  bases,  as  they  are  well  known  to  do,  and  hence  they  react  as 
either  adds  or  bases  under  different  conditions. 

It  must  not  be  imagined  that  the  structure  of  the  complete 
molecule  is  simply  a  long  straight  chain  of  amino-acids  joined 
only  in  the  same  way  as  are  the  components  of  glycylglycin.1 
The  existence  of  the  diamino-acids,  of  the  benzene  rings,  of 
hydroxyl  groups,  (as  in  serin  ortyrosin),  of  ring  compounds,  (as 
pyrrolidintcarboxylic  acid),  of  substances  with  two  acid  groups, 
(as  glutaminic  and  aspartic  acid),  adds  complications  to  the  forma- 
tion until  it  is  impossible  to  estimate  just  how  all  the  various 
building  stones  may  be  arranged.  We  must  bear  in  mind  the 
size  of  the  proteid  molecule,  which  Hofmeister  has  estimated  (for 
serum  albumin)  as  having  a  molecular  weight  of  10,166,  and 
for  hemoglobin  the  molecular  weight  has  been  estimated  at 
16,669.  Within  such  a  "giant  molecule"  there  is  room  for 
variety  almost  beyond  computation. 

The  Proteids  of  the  Cell. — By  physiological  chemists 
proteids  are  classified  into  simple  proteids,  of  which  egg  and 
serum  albumin  are  types  :  and  compound  proteids,  which  are 
characterized  by  having  some  special  non-proteid  group  which 
can  be  split  off,  leaving  behind  a  characteristic  proteid  residue, 
e.  g.,  nucleo-proteids,  glyco-proteids.  As  primary  cell  constit- 
uents the  following  varieties  of  proteids  may  be  mentioned  : 
albumin,  globulin,  nucleo-proteid,  nucleo-albumin  or  phospho- 
proteid,  and  coagulated  proteids.  At  one  time  it  was  thought 
that  cytoplasm  consisted  chiefly  of  albumin,  like  white  of  egg, 
but  we  now  know  that  this  forms  but  a  small  part  of  the  cell 
proteids,  often  occurring  only  as  traces.  It  is  held  by  some 
that  true  albumin  occurs  only  as  a  building  or  intermediate 
cleavage  product  of  the  more  complicated  forms  of  cellular 
proteids,  and  is  itself  of  relatively  slight  importance  in  cell 
life,  not  participating  in  chemical  changes  except  as  a  food-stuff. 

Albumins  are  characterized  chiefly  by  their  greater  solubility 
in  water,  and  in  being  less  easily  precipitated  than  most  proteids. 
They  seem  to  be  a  fundamental  type  of  proteids.  The  three 
forms  of  albumin  that  have  been  described  in  animal  tissues  or 
products  are  egg -albumin,  lactalbumin  of  milk,  and  serum 

1  Fisher  and  Abderhalden  (Ber.  deut  Chem.  GeselL,  1906  (39),  752)  have 
described  a  polypeptid  in  which  the  union  of  the  amino-acids  is  accomplished 
in  a  somewhat  different  manner,  as  shown  by  the  formula  : 


CH2  -  COOH  +  CH3  —  CH— COOH  =  HN 


CH2—  or 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL         25 

albumin  ;  probably  cell  albumin  is  most  closely  related  to  the 
last,  and  what  has  been  described  as  cell  albumin  is  perhaps  in 
many  cases  but  serum  albumin  that  has  been  imperfectly 
removed. 

Globulins  also  occur  in  all  cells,  but  in  small  amounts  in 
most  animal  cells  except  the  muscles,  whose  chief  proteids 
belong  to  this  or  a  closely  related  group.  The  globulins  are 
quite  similar  to  the  albumins,  so  that  there  is  really  no  sharp 
line  between  the  two  groups.  Their  insolubility  in  water 
separates  them  from  albumins,  and  their  solubility  in  dilute 
neutral  salt  solutions  from  the  more  complex  proteids.  An 
important  feature  of  the  globulins  is  the  low  temperature  at 
which  they  coagulate — some  so  low  that  Halliburton  l  believes  it 
possible  that  they  may  be  coagulated  within  the  cells  during 
high  fevers. 

Hammarsten  has  long  maintained  that  simple  proteids  form 
a  relatively  insignificant  part  of  the  cytoplasm,  in  opposition  to 
the  once-prevalent  view  that  the  nucleo-proteids  were  limited  to 
the  nucleus,  and  that  the  cytoplasm  was  chiefly  albumin  and 
globulin.  The  general  trend  of  opinion  as  influenced  by  the 
results  of  researches  has  been  favorable  to  his  contentions,  and 
we  shall  probably  not  be  far  wrong  in  accepting  his  statement 
that — "  The  chief  mass  of  the  protein  substances  of  the  cells 
does  not  consist  of  proteids  in  the  ordinary  sense,  but  consists 
of  more  complex  phosphorized  bodies,  and  that  the  globulins 
and  albumins  are  to  be  considered  as  nutritive  materials  for  the 
cells  or  as  destructive  products  in  the  chemical  transformation 
of  the  protoplasm/' 

Nucleo-proteids  are  probably  the  most  important  constituents 
of  the  cell,  both  in  quantity  and  in  relation  to  cell  activity. 
The  enzymes  seem  to  be  nucleo-proteids,  or  at  least  they  are 
intimately  associated  with  them.  (See  further  discussion  under 
the  subject  of  enzymes.)  In  structure  the  nucleo-proteids  are 
very  complex,  as  indicated  by  the  different  products  yielded  on 
hydrolytic  cleavage  of  the  molecule.  Furthermore,  there  are 
many  varieties,  depending  both  upon  the  nature  and  proportions 
of  the  component  parts.  They  may  be  described  as  consisting 
of  two  primary  constituents — (1)  nucleic  acid  and  (2)  a  proteid 
body,  in  chemical  combination  with  each  other  like  a  salt.  In 
the  chro matin  structures  of  the  nucleus  the  proportion  of  proteid 
in  the  nucleo-proteid  is  small,  so  that  these  bodies  have  a 
strongly  acid  character,  as  indicated  by  their  affinity  for  basic 

1  Halliburton  and  Mott,  Archives  of  Neurology,  1903  (2),  727 ;  also  see 
Halliburton' s  "  Chemistry  of  Muscle  and  Nerve.  " 


26  INTRODUCTION 

stains.  In  the  cytoplasm,  on  the  other  hand,  the  nucleo-proteids 
have  the  acid  quite  saturated  with  proteids  and  hence  are  devoid 
of  acid  properties,  which  is  also  indicated  by  their  lack  of 
affinity  for  hematoxylin  and  other  basic  dyes.  The  term  nucleic 
acid  also  covers  a  large  group  of  substances,  which  are  charac- 
terized, on  the  one  hand,  by  their  frequent  occurrence  bound  with 
proteids,  and,  on  the  other  hand,  by  their  yielding  phosphoric 
acid  and  purin  bases,  pyrimidins  and  pentoses  on  cleavage. 
Diagram matically  the  manner  of  cleavage  of  the  nucleo-proteids 
may  be  indicated  as  follows  : 

Nucleoproteid 

nuclein l         proteid 
nucleic  acid         proteid 
phosphoric  acid         purin  bases,  pyrimidins  and  pentoses. 

The  enormous  variety  of  nucleo-proteids  that  may  possibly 
exist  can  be  imagined  when  we  consider  that  there  exist  several 
different  sorts  of  purin  bases,  not  all  of  which  are  found  in 
any  one  nucleic  acid,  that  the  form  of  phosphoric  acid  present 
may  vary,  that  the  proteids  are  of  different  varieties,  that  the 
proportions  of  each  ingredient  is  perhaps  never  twice  the  same, 
and  furthermore  that  many  nucleo-proteids  contain  carbohydrate 
groups.  The  possible  combinations  of  these  ingredients  is  little 
short  of  infinite  and  it  may  well  be  that  we  have  here  a  partial 
explanation  of  the  innumerable  varieties  of  living  organisms.2 

In  the  cell  the  nucleo-proteids  probably  exist  partly  as  solid 
structures,  e.  g.,  the  chromatin  framework  of  the  nucleus,  and 
partly  dissolved  in  the  plasma.  An  interesting  phenomenon  is 
the  alteration  in  the  chromatin  nucleo-proteids  during  cell 
division,  when  they  seem  to  lose  part  of  the  combined  proteid 
and  approach  more  nearly  pure  nucleic  acid — -just  as  inorganic 
salts  occur  with  the  acids  and  bases  saturating  each  other  more 
or  less  incompletely,  e.  <r/.,  mono-,  di-,  and  tribasic  phosphates. 
In  this  we  have  a  chemical  explanation  of  the  intensity  of  the 
staining  of  dividing  nuclei  by  basic  dyes. 

Nucleo-proteids  combined  with  carbohydrates,  nucleo-gluco- 
proteids,  are  probably  important  and  perhaps  constant  cell  con- 
stituents. It  is  of  interest  to  note  that  the  carbohydrate  is 
often  not  one  of  the  ordinary  hexoses,  such  as  glucose,  but  one 
of  the  more  uncommon  pentoses. 

1  Probably  nuclein  should  be  considered  as  merely  one  variety  of  nucleo- 
proteid,  with  less  proteid  than  the  other  varieties. 

2  The  chemistry  of  the  nucleo-proteids  is  also  discussed  in  the  chapter  on 
Uric  Acid  Metabolism  and  Gout,  Chap.  XXI. 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL        27 

Nucleo=albumins  (or  phospho-proteids),  by  an  unfortunate 
similarity  of  name,  are  often  confused  with  nucleo-proteids  by 
non-chemical  writers,  a  difficulty  increased  by  an  actual  resem- 
blance to  the  extent  that  they  also  yield  phosphoric  acid,  and 
are  somewhat  similar  in  solubility  and  digestibility.  They  are 
essentially  different,  however,  in  that  they  do  not  yield  nucleic 
acid  or  purin  bases  on  cleavage.  Probably  members  of  this 
group  are  also  constant  components  of  cells. 

Glycoproteids  (or  gluco-proteids)  and  phospho-glycoproteids 
are  also  believed  to  occur  frequently  or  constantly  in  proto- 
plasm. They  are  compounds  of  proteids  with  a  sugar  or  sugar- 
like  group,  which  probably  usually  contains  nitrogen,  thus 
differing  from  the  ordinary  hexoses  and  pentoses. 

Insoluble  proteids,  or  bodies  resembling  the  coagulated  pro- 
teids in  their  lack  of  solubility  in  various  fluids,  are  left  behind 
after  the  other  proteids  have  been  extracted  from  the  cells. 
Their  significance  is  not  known  :  whether  to  a  large  extent  arti- 
ficially produced  or  whether  a  normal  structural  element  of  the 
cell. 

FATS  AND  LIPOIDS 

Ordinary  fats  occur  in  nearly  all  cells,  and  probably  in  all, 
but  their  demonstration  is  not  readily  possible.  The  micro- 
scopic appearance  of  a  cell,  even  when  special  stains  for  fat  are 
used,  gives  no  correct  idea  of  the  amount  of  fat  actually  present. 
Thus  normal  kidneys  contain  15  to  18  per  cent,  of  fat  in  their 
dry  substance,  but  none  of  this  can  be  detected  with  the  micro- 
scope. A  kidney  which  seems  microscopically  the  site  of  marked 
fatty  degeneration  may  show  no  more  fat  when  examined  chem- 
ically than  a  normal  kidney,  which  in  section  appears  to  be 
quite  free  from  fat.  This  is  because  some  of  the  intracellular 
fat  is  bound  chemically  with  the  proteids,  and  when  so  bound 
it  cannot  be  seen,  nor  can  it  be  stained  by  the  dyes  used  for 
that  purpose ;  only  when  degenerative  changes  of  certain  kinds 
have  liberated  it  from  combination  does  it  become  visible  and 
stainable  (Rosenfeld).  Whether  the  intracellular  fat  has  any 
function  other  than  that  of  serving  as  a  food-stuff  is  not  known, 
but  there  can  be  no  question  of  the  importance  of  the  phosphor- 
ized  fat,  lecithin. 

Lecithin  is  a  primary  cell-constituent,  and  is  probably  im- 
portant both  in  metabolism  and  physically.  Hammarsten 
regards  it  as  concerned  in  the  building  up  of  the  nucleus.  As 
will  be  shown  later,  many  of  the  most  essential  physical  proper- 
ties of  the  living  cell  depend  upon  the  presence  in  it  of  lipoids, 
of  which  lecithin  is  apparently  the  chief.  Of  the  ether-soluble 


28  INTRODUCTION 

substances  in  the  heart,  for  example,  60  to  70  per  cent,  is  leci- 
thin, which  constitutes  about  8  per  cent,  of  the  dry  weight  of 
the  myocardium. 

There  are  several  varieties  of  lecithin,  depending  upon  the 
fatty  acid  radical  they  contain,  and  for  the  group  Koch  has 
proposed  the  name  of  ledihans. 

The  structural  formula  of  one  lecithin,  stearyloleyl  lecithin, 
is  as  follows : 

CH2-0-C18-H350 
CH  —  O  —  C18-H330 
CH2  — O  — PO  — OH 

O  —  CH2  —  CH2  —  N  =  (CH3)3. 
N>H 

It  differs  from  ordinary  fats,  therefore,  in  having  two  special 
groups,  one  the  phosphoric  acid,  the  other  the  cholin  radical, 
which  last  seems  to  be  of  no  little  importance  in  pathological 
processes.  In  its  physical  properties  it  is  quite  similar  to  the 
ordinary  fats,  although  it  forms  even  finer  emulsions  in  water, 
which  are  practically  colloidal  solutions  (W.  Koch). 

Cephalin,  a  closely  related  body  differing  in  having  but  one 
methyl  group,  is  also  probably  as  widely  spread  in  the  tissues 
as  lecithin,  according  to  Koch  and  Woods.  * 

Cholesterin,  which  is  another  lipoid,  is  nearly  as  universally 
present  as  lecithin.2  There  are  probably  several  varieties  of 
cholesterin,  wrhich  exist  both  free  and  in  combination  with  fatty 
acids,  for  cholesterin  is  an  alcohol  and  not  at  all  similar  to  the 
fats  chemically,  although  very  similar  physically.  The  empiri- 
cal formula  is  C27H44O  (or  C^H^O)  and  it  is  possibly  related 
to  the  terpenes.  It  seems  to  be  quite  inert  chemically,  and 
therefore  is  probably  important  only  because  of  its  effect  on  the 
physical  properties  of  the  cells.  By  some  it  is  considered  to  be 
a  decomposition  or  cleavage  product  of  the  proteids,  which  is  in 
accordance  with  its  abundance  in  masses  of  old  necrotic  tissue, 
e.  g.j  atheromatous  masses,  old  infarcts,  and  old  exudates. 

Protagon,  which  name  probably  covers  a  group  of  nitrogen- 
ous, phosphorized  bodies,  (Gies3),  occurs  in  many  or  all  cells, 
but  especially  in  the  nervous  tissues.  The  properties  of  prota- 
gon  are  in  general  similar  to  the  other  lipoid s,  but  its  exact 

1  Jour.  Biol.  Chem.,  1905  (1),  203. 

2  Recent  literature  given  by  Abderhalden  and  Le  Count,  Zeit.  exp.  Path, 
u.  Pharm.,  1905  (2),  199. 

3  Jour.  Biol.  Chem.,  1905  (1),  59. 


THE  CHEMISTRY  AND  PHYSICS  OF  TH&  CELL         29 

composition  is  evidently  too  uncertain  to  permit  of  surmises  as 
to  its  special  purpose. 

Jecorin,  which  is  generally  considered  as  a  combination  of 
lecithin  and  glucose,  is  probably  also  not  a  definite  compound, 
according  to  the  most  recent  observations.  1 

CARBOHYDRATES 

The  third  great  class  of  food-stuffs,  the  carbohydrates,  is 
represented  in  the  cell  by  pentoses  and  hexoses  combined  with 
proteids  and  with  lipoids,  and  also  by  glycogen,  which  exists 
free.  Glycogen  is  a  rather  difficult  substance  to  isolate,  and, 
therefore,  although  it  is  not  found  in  all  cells  by  our  present 
methods,  yet  it  may  well  be  that  it  is  a  constant  constituent  of 
the  protoplasm.  There  is  no  evidence,  however,  that  it  is  any- 
thing more  than  a  source  of  heat  and  energy  to  the  cell.  Its 
properties  and  occurrence  will  be  considered  more  fully  in  the 
discussion  of  glycogenic  infiltration.  Since  glycogen  is  formed 
from  dextrose  and  is  constantly  breaking  down  into  dextrose,  it 
is  probable  that  the  latter  is  also  constantly  present  in  the  cells. 

INORGANIC  SUBSTANCES 

Up  to  this  point  the  substances  of  the  cytoplasm  that  have 
been  discussed  have  all  been  organic  compounds  which  do  not 
naturally  exist  independent  from  living  or  once  living  cells,  yet 
the  inorganic  substances  of  the  protoplasm  are  also  of  vital 
importance.  As  Mann  says,  "  so-called  pure  ash-free  proteids 
are  chemically  inert,  and,  in  the  true  sense  of  the  word,  dead 
bodies.  What  puts  life  into  them  is  the  presence  of  electro- 
lytes." The  various  salts  of  potassium,  sodium,  calcium,  mag- 
nesium, and  iron  which  all  cells  contain  do  not  exist  merely 
dissolved  in  the  water  of  the  cell,  but  in  part  they  are  combined 
with  the  organic  constituents  of  the  protoplasm.  They  are  not 
combined  as  simple  additions  of  the  salts  to  the  proteids ;  but 
ions,  both  anions  and  kations  are  united  in  chemical  combina- 
tion to  the  large  proteid  molecule  (ion-proteids).  Possibly 
the  proteids  participate  in  vital  chemical  processes  only  as  ion 
compounds  with  inorganic  elements.  It  is  extremely  difficult, 
indeed  almost  impossible,  to  secure  proteids  entirely  free  from 
inorganic  substances  (ash-free  proteids).  The  fact  that  the  in- 
organic substances  are  held  in  the  cells  chemically  rather  than 
by  simple  diffusion  into  them  from  the  surrounding  fluids  is 
shown  by  the  great  difference  in  the  proportions  of  various  salts 

•Meinertz,  Zeit.  physiol.  Chem.,  1905  (46),  376;  Siegfried  and  Marx,  Ibid, 
1906  (46),  492. 


30  INTRODUCTION 

in  the  cells  and  in  the  extra-cellular  fluids.  Thus  potassium  is 
nearly  always  much  more  abundant  in  the  cells  than  in  the  tissue 
fluids,  while  sodium  is  more  abundant  in  the  fluids.  Phos- 
phoric acid  is  also  more  abundant  in  the  cells,  and  chlorin  in 
the  plasma.  In  cells  iron  seems  to  exist  chiefly  in  combination 
with  the  nucleo-proteids.  These  matters  will  be  taken  up  in 
greater  detail  in  considering  the  physical  chemistry  of  the  cell. 

THE  PHYSICAL  CHEMISTRY  OF  THE  CELL  AND  ITS  CON- 
STITUENTS 

From  the  standpoint  of  physical  chemistry  the  cell  consists 
of  a  collection  of  colloids  and  crystalloids,  electrolytes  and 
non-electrolytes,  dissolved  in  water,  in  lipoids,  and  in  each 
other,  surrounded  by  a  semipermeable  membrane,  and  per- 
haps subdivided  by  similar  membranes.  Physical  chemical 
processes,  as  we  shall  see  later,  play  an  all-important  part  in 
the  life  phenomena  of  the  cell,  and  therefore  some  space  may 
profitably  be  occupied  in  explaining  the  nature  of  these  changes 
and  of  the  substances  that  participate  in  them. 

CRYSTALLOIDS  AND  THEIR  PROPERTIES 

Crystalloids,  .or  substances  that  tend  under  favorable  condi- 
tions to  form  crystals,  and  which  diffuse  readily  through  most 
diffusion  membranes,  form  a  relatively  small  part  of  the  total 
mass  of  the  cell,  but  they  are  fully  as  essential  as  the  col- 
loids. The  chief  representatives  of  this  group  that  are  found 
usually  or  constantly  in  the  cell  are  the  inorganic  salts,  sugar, 
and  the  innumerable  decomposition  products  of  the  proteids, 
including  particularly  urea,  creatin,  purin  bases,  ammo-acids, 
etc.  Most  of  these  are  by  no  means  so  characteristic  of  living 
things  as  are  the  colloids,  sometimes  occurring  quite  independ- 
ently of  a  cellular  origin,  which  the  proteids  never  do.  The 
inorganic  salts  in  particular  seem  quite  foreign  to  livingprocessesr 
and  as  they  enter  and  leave  the  body  practically  unchanged  they 
are  evidently  not  a  source  of  energy  through  chemical  change. 
Their  importance  to  the  cell  lies  almost  entirely  in  their  physi- 
cal or  physico-chemical  properties.  The  organic  crystalloids, 
although  of  nutritional  value,  also  have  physical  properties  in 
some  respects  similar  to  those  of  the  inorganic  crystalloids,  and 
therefore  to  this  extent  they  exert  similar  influences,  but  the 
essential  difference  between  the  organic  and  the  inorganic 
crystalloids  is  that  all  the  latter  are  electrolytes,  while  many 
of  the  organic  crystalloids  that  occur  in  cells  are  non-electro- 
lytes. The  importance  of  this  distinction  lies  not  in  the  utility 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL        31 

or  non-utility  of  these  substances  as  conductors  of  electrical 
currents  in  the  ordinary  sense,  but  rather  on  the  existence  of 
those  properties  which  determine  their  conductive  ability. 
Electrical  conductivity  is  an  index  of  ionization,  and  upon 
ionization  depends  the  chief  influence  of  the  electrolytes  upon 
vital  activities. 

Electrolytes  and  Non-electrolytes.  Ionization.  — 
If  we  attempt  to  pass  a  current  of  electricity  through  water, 
we  find  that  it  meets  a  great  resistance,  and  the  purer  the 
water,  the  greater  the  resistance.  In  water  as  pure  as  can 
possibly  be  obtained  the  resistance  of  a  layer  only  one  milli- 
meter thick  has  been  found  equal  to  that  of  a  copper  wire  of 
equal  cross-section  long  enough  to  reach  around  the  earth  one 
thousand  times.1  The  addition  of  the  slightest  quantity  of  salts, 
acids,  or  alkalies  increases  the  conductivity  enormously,  and  in 
any  considerable  amounts  they  make  the  solution  an  excellent 
conductor  of  an  electric  current.  On  the  other  hand,  by  the 
addition  of  sugar  or  alcohol  to  the  water,  the  conductivity  is  in- 
creased very  little  or  not  at  all.  What  differences  exist  between 
the  soluble  substances  that  do  increase  the  conductivity  of  the 
solution  and  those  that  do  not  ? 

If  we  dissolve  in  water  in  a  platinum  dish  a  small  quantity 
of  an  electrolyte,  say  copper  sulphate,  and  pass  a  current  of 
electricity  through  it,  using  the  platinum  dish  as  the  negative 
electrode  and  inserting  the  positive  electrode  in  the  solution,  it 
will  be  found  after  a  short  time  that  there  is  no  longer  a  blue 
solution  of  copper  sulphate  in  the  dish,  but  rather  that  the 
lining  of  the  dish,  where  it  is  under  the  liquid,  has  become  red 
from  the  deposition  of  a  thin  layer  of  copper.  If  we  reverse 
the  current,  it  will  be  found  that  the  copper  leaves  the  surface 
of  the  dish  to  collect  upon  the  electrode  inserted  in  the  water, 
which  is  now  the  negative  pole.  This  experiment  illustrates 
the  ability  of  the  copper  to  wander  from  one  electrode  to 
another,  and  it  is  by  this  wandering  that  the  electricity  is  carried 
by  the  copper  particles.  The  copper  sulphate  is  dissociated 
into  its  two  parts :  copper,  carrying  a  positive  charge  which 
goes  to  the  negative  pole  or  cathode,  and  is  therefore  called  the 
positive  ion,  or  cation  ;  SO4,  carrying  a  negative  charge,  wanders 
to  the  anode,  and  is  therefore  called  the  negative  ion  or  anion. 
The  individual  particles  which  carry  the  charges  are  designated 
as  ions.  It  will  be  noted  that  the  particles  may  or  may  not  be 
single  atoms  ;  in  the  case  of  copper  sulphate  the  cations 
(copper)  are  atoms,  but  the  anion,  SO4,  is  formed  by  several 

1  Kohlrausch  and  Heydweiller,  quoted  by  Cohen. 


32  INTRODUCTION 

atoms  grouped  together.  Sometimes  the  ion  consists  of  a  great 
number  of  atoms,  as  when  such  a  molecule  as  stearic  acid  dis- 
sociates we  have  ions  of  hydrogen  and  ions  of  C^H^O^  In 
general,  if  the  ion  is  very  large,  its  movement  is  relatively  slow, 
and  it  shows  less  pronounced  chemical  properties. 

Now,  although  the  migration  of  the  ions  to  the  electrodes  has 
been  known  for  a  very  long  time,  the  important  fact  that  the 
separation  of  a  substance  into  its  ions  is  not  brought  about 
primarily  by  the  electric  current  was  ascertained  later.  It  is 
not  the  passage  of  the  current  that  splits  up  the  electrolyte,  but 
rather  it  is  because  the  substance  has  already  been  split  by  the 
solvent  into  its  ions  that  it  conducts  the  current.  When  we 
dissolve  an  electrolyte,  say  sodium  chloride,  in  water,  many  of 
the  molecules  split  into  the  cation  Na,  and  the  anion  Cl.  If 
the  solution  is  very  dilute,  the  dissociation  may  be  complete,  and 
we  have  no  molecules  of  NaCl  in  our  solution  at  all,  but  merely 
the  two  sorts  of  ions  in  rapid  motion.  If  the  solution  is  more 
concentrated,  a  larger  proportion  remains  undissociated,  although 
the  total  number  of  ions  may  be  much  greater.  What  the 
electric  current  does  in  passing  through  such  a  solution  is  to 
cause  a  migration  of  ions  toward  the  respective  poles,  where 
they  accumulate ;  as  a  result,  the  solution  between  the  poles 
contains  fewer  ions  than  it  should  and  the  molecules  undergo  con- 
tinuous dissociation  until  they  have  finally  disappeared,  for  the 
ions  are  all  collected  about  the  poles  as  fast  as  formed,  and 
finally  the  solution  becomes  free  from  both  molecules  and  ions 
except  in  the  vicinity  of  the  poles.  So  complete  is  this  migra- 
tion that  the  most  accurate  method  of  quantitative  estimation 
of  many  metals,  such  as  copper,  is  this  electrolytic  method,  by 
which  we  can  cause  all  the  copper  ions  to  become  attached  to 
the  inner  surface  of  a  weighed  platinum  dish,  and  after  washing 
away  the  solution  and  drying  we  can  determine  accurately  the 
amount  of  copper  that  has  been  attached  to  the  dish. 

It  is  the  act  of  solution,  then,  and  not  the  electric  current, 
that  causes  ionization,  and  so  every  solution  of  an  electrolyte, 
such  as  a  physiological  salt  solution,  or  sea  water,  or  urine,  or 
any  secretion  of  the  body,  contains  a  greater  or  less  number  of 
free  ions.  In  y—  salt  solution,  which  is  nearly  the  same  concen- 
tration as  physiological  salt  solution  (its  strength  is  0.58  per 
cent.),  the  amount  of  dissociation  is  so  great  that  84  per  cent, 
of  the  molecules  of  NaCl  have  been  changed  into  the  ionic 
form  and  but  16  per  cent,  remain  as  molecules  at  room  temper- 
ature. Evidently,  since  it  is  the  solvent  that  causes  the  dis- 
sociation, the  nature  of  the  solvent  will  make  a  great  difference 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL         33 

in  the  amount  of  dissociation.  Water  is  the  best  known  medium 
for  causing  dissociation,  except  possibly  peroxide  of  hydrogen, 
while  chloroform  and  alcohol  are  relatively  very  weak  in  this 
respect.  The  amount  of  dissociation  is  also  increased  by 
raising  the  temperature. 

The  importance  of  this  process  of  dissociation  or  ionization 
lies  in  the  fact  that  with  most  substances  no  chemical  reaction 
can  occur  while  the  substance  is  in  the  non-ionized  state.  .The 
chemical  properties  of  ionizable  substances  are  produced  largely 
by  the  ions  they  liberate  on  dissociation.  Acids  owe  their 
character  to  the  hydrogen  ion,  alkalies  owe  theirs  to  the  hydroxyl 
ion.  We  can  appreciate  the  difference  between  the  ions  and 
the  same  substance  in  the  non-ionized  form  if  we  consider  the 
chemical  inertness  of  hydrogen  gas,  as  compared  with  a  solution 
of  acid  which  owes  its  powerful  eifects  to  hydrogen  ions. 
Perfectly  dry  sulphuric  acid  is  absolutely  free  from  the  acid 
properties  that  characterize  it  when  it  contains  a  little  water, 
because  it  is  not  ionized  when  dry.  It  is  for  the  same  reason 
that  we  can  have  two  substances  together  in  a  dry  condition 
without  reaction,  that  would  immediately  react  if  moist.  It 
is  by  means  of  the  electrical  charges  of  the  ions  that  chemical 
reactions  occur,  and  hence  ions  must  be  present  to  have  reactions. 
As  a  consequence,  the  physiological  eifects  of  electrolytes  are 
due  to  their  ionic  condition,  and  through  the  ions  that  are 
present  in  the  cell  many  of  its  various  chemical  processes  are 
brought  about.  Not  all  substances  ionize  with  the  same  readiness, 
which  causes  a  great  difference  in  their  properties.  The  reason 
that  acetic  acid  is  a  weaker  acid  than  hydrochloric  acid  is  that 
it  does  not  ionize  to  such  an  extent,  and  so  a  corresponding 
quantity  does  not  introduce  as  large  a  number  of  hydrogen  ions 
into  a  solution.  Larger  molecules,  as  a  rule,  ionize  less  than 
smaller  ones  of  similar  nature,  e.  g.,  stearic  acid  ionizes  less  than 
acetic  acid  and  therefore  is  a  weaker  acid.  Likewise  the 
properties  of  a  substance  which  depend  upon  its  ions  will  be 
less  marked  when  it  is  in  a  solvent  that  produces  little  ionization. 
For  example,  bichloride  of  mercury  owes  its  antiseptic  properties 
to  the  Hg  ions  that  it  sets  free  when  in  solution.  It  is  well 
known  that  solutions  of  mercury,  and  for  that  matter  most  other 
antiseptics,  are  much  less  actively  germicidal  in  alcohol  than 
when  in  water,  because  their  ionization  is  less  in  alcohol;  and 
the  germicidal  properties  decrease  as  the  proportion  of  alcohol 
increases,  until  the  germicidal  effect  of  the  mixture  is  no  greater 
than  that  of  alcohol  alone  in  the  same  strength. 

If  we  had  no  electrolytes  in  the  cell,  electric  charges  could 
3 


34  INTRODUCTION 

not  be  carried  about  in  it,  and  hence  chemical  reactions  could 
not  occur.  It  is  this  fact  that  makes  the  inorganic  salts  of  such 
vital  importance  to  the  cell  life.  To  repeat  Mann's  words,  it 
is  the  electrolytes  that  put  life  into  the  proteids.  Water  itself 
is  almost  absolutely  nondissociated,  and  proteids  so  little  that 
for  some  time  it  was  doubted  if  they  really  did  ionize.  Probably 
all  soluble  substances  do  dissociate  to  a  certain  minimal  degree, 
but  it  is  so  slight  for  most  of  the  constituents  of  the  cell  except 
the  inorganic  salts  (the  organic  acids  and  alkalies,  and  a  few 
dissociable  organic  products  of  proteid  metabolism,  occur  in 
such  insignificant  amounts  as  to  be  almost  negligible)  that 
without  them  there  would  be  little  chemical  activity  possible, 
and  hence  life  would  be  absent  or  at  a  very  low  ebb  indeed. 
As  before  mentioned,  the  inorganic  salts  probably  exist  in  the 
cell  not  only  as  salts,  but  also,  and  perhaps  chiefly,  as  ions 
and  ionic  compounds  with  the  cell  proteids.  For  the  most 
part  it  seems  to  be  the  cations  that  play  the  chief  role  in  forming 
ion-proteid  compounds,  although  undoubtedly  the  anions  do 
combine  with  the  proteids  also,  and  in  some  instances  they  exert 
very  characteristic  and  important  effects ;  e.  g.}  the  differences 
between  the  effects  of  chlorides,  bromides,  and  iodides,  or  of 
CNH  as  compared  with  HC1,  both  of  which  liberate  the  same 
cation  and  differ  only  in  their  anions. 

Many  applications  of  the  facts  and  theories  of  ionization 
have  been  made  in  physiology,  as,  for  example,  the  observation 
of  Kahlenberg  and  True  that  taste  is  produced  by  ions  rather 
than  by  whole  molecules;  of  Loeb,  on  the  effects  of  ions  upon 
the  taking  up  of  water  by  the  cells  and  tissues,  their  effects 
upon  muscular  contractions,  and  upon  cell  multiplication  and 
fertilization;  of  Mathews,  upon  the  transmission  of  nervous 
impulses  ;  of  Hardy,  upon  the  effects  of  ions  on  coagulation  and 
precipitation  of  colloids.  A  few  applications  have  also  been 
made  in  pathology,  especially  the  relation  of  ions  to  edema,  to 
diuresis  and  glycosuria,  and  also  to  problems  of  immunity. 
No  attempt  will  be  made  here  to  go  further  into  the  observations 
and  theories  concerning  ionization  or  its  role  in  physiology,  but 
for  more  extensive  information  as  well  as  for  the  complete 
bibliography  the  works  mentioned  below  may  be  referred  to.1 

1  "  Physical  Chemistry  for  Physicians  and  Biologists, "  Cohen.  American 
translation  by  M.  H.  Fischer,  1903;  New  York.  "  Physikalische  Chemie 
der  Zelle  und  der  Gewebe, "  Hpber,  Leipzig,  1902.  "  Osmotische  Druck 
und  lonenlehre  in  den  medicinischen  Wissenschaften, "  Hamburger,  Wies- 
baden, 1902.  "Studies  in  General  Physiology,"  Loeb,  University  of  Chicago 
Press,  1905.  "Dynamics  of  Living  Matter,"  Loeb,  Columbia  University 
Press,  New  York,  1906. 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL         35 

The  applications  in  pathology  will  be  brought  out  as  the  sub- 
ject under  discussion  in  subsequent  chapters  necessitates,  and  it 
is  largely  to  facilitate  the  understanding  of  such  references  that 
this  brief  summary  of  the  subject  of  ionization  has  been 
introduced.  In  the  same  spirit  we  take  up  the  subjects  of 
diffusion  and  osmosis. 

Diffusion  and  Osmosis. — Although  the  non-electrolytes 
do  not  ionize  to  any  considerable  extent,  and  therefore  are  rela- 
tively inactive  chemically,  the  crystalloidal  non-electrolytes,  of 
which  sugar  and  urea  are  the  two  chief  examples  among  the 
cell  constituents,  possess  in  common  with  the  electrolytes  the 
important  property  of  diffusion.  By  this  process  the  exchange 
of  chemical  substances  between  the  blood  and  the  cell  is  brought 
about,  by  it  the  chemical  composition  of  the  different  parts  of 
the  cell  and  between  different  cells  is  equalized,  and  without  it 
chemical  change  would  be  practically  impossible.  Diffusion 
occurs  most  simply  between  two  solutions  of  unlike  nature,  or 
between  a  solution  of  a  substance  and  the  solvent  alone,  when 
placed  in  contact  with  one  another.  If  we  place  in  the  bottom 
of  a  cylindrical  vessel  a  solution  of  copper  sulphate  and  above 
it  some  water,  carefully  avoiding  mixing,  it  will  be  found  after 
some  time  that  the  fluid  has  become  equally  blue  throughout. 
This  is  brought  about  by  the  movement  of  the  dissolved  parti- 
cles, which  gradually  carries  them  through  the  entire  mass  of 
fluid,  and  as  their  migration  is  against  the  force  of  gravity,  they 
evidently  accomplish  work.  This  process  is  not  dependent 
upon  ionization,  for  a  solution  of  cane-sugar  or  of  urea  will 
show  the  same  diffusion.  A  solution  of  proteid  or  other  colloid 
does  so  much  more  slowly,  however,  indeed  quite  imperceptibly. 

If  we  were  to  introduce  a  piece  of  filter-paper  between  the 
water  and  the  copper  sulphate  solution,  the  diffusion  would  go 
on  the  same,  the  pores  of  the  paper  permitting  the  passage  of 
the  molecules  without  hindrance.  If,  instead  of  filter-paper, 
there  were  introduced  a  sheet  of  some  substance  free  from 
pores,  then  diffusion  .would  be  much  more  affected.  If  the  sep- 
tum was  of  such  a  nature  that  the  substances  in  solution  were 
insoluble  in  it  (e.  g.,  glass),  diffusion  would  of  necessity  stop ; 
but  if  it  were  something  in  which  the  solvent  or  the  solute  was 
soluble,  such  as  a  gelatin  plate,  then  these  substances  would  dis- 
solve in  it,  and  diffusing  through  its  substance  escape  into  the 
fluid  on  the  other  side.  The  last  example  indicates  the  condi- 
tions afforded  in  the  animal  cell,  and  also  in  the  usual  labora- 
tory diffusion  experiments  when  the  membrane  is  generally 
either  an  animal  membrane  or  a  parchment  paper,  both  of 


3  6  INTE  OD  UCTION 

which  are  composed  of  colloids.  Crystalloids  are  generally 
soluble  in  colloids  and  hence  pass  through  such  diffusion  mem- 
branes ;  colloids  dissolve  but  slightly  in  colloids,  and  hence 
they  do  not  pass  through  a  diffusion  membrane  readily,  and  are, 
therefore,  but  very  slightly  diffusible. 

The  process  of  diffusion,  if  uninterrupted,  always  continues 
until  the  solution  is  of  exactly  the  same  composition  through- 
out. If  on  one  side  of  the  diffusion  membrane  there  is  a  sub- 
stance that  passes  through  the  membrane  rapidly,  and  on  the 
other  a  substance  that  passes  through  slowly  or  not  at  all,  there 
will  soon  be  an  unequal  condition  on  the  two  sides  of  the 
membrane,  for  the  diffusible  substance  would  accumulate  in 
equal  amounts  on  each  side,  while  the  non-diffusible  would 
remain  where  it  was.  On  one  side  there  would  then  be  more 
material  exerting  osmotic  pressure  than  on  the  other,  and  if 
the  membrane  were  flexible,  it  would  bulge  toward  the  opposite 
side.  The  pressure  is  due  to  the  bombardment  of  the  contain- 
ing walls  by  molecules  or  ions  of  the  substances  in  solution, 
and  hence  the  more  molecules  and  ions  in  a  solution,  the  more 
pressure.  When  equal  numbers  of  particles  are  on  each  side  of 
the  partition,  the  pressure  is  equalized.  It  is  quite  possible  to 
have  membranes  permeable  to  one  substance  and  not  to  another  ; 
such  membranes  are  called  semipermeable.  Experimentally 
they  are  usually  produced  as  follows  :  A  cup  or  cylinder  of 
porous  clay,  such  as  the  cylinder  of  a  Pasteur-Chamberland 
filter,  is  filled  with  a  solution  of  some  substance  and  placed  in 
a  solution  of  another  substance,  which,  by  reacting  with  the 
first  where  they  meet  in  the  wall  of  the  cylinder,  forms  the 
proper  sort  of  a  precipitate — most  frequently  copper  sulphate 
and  potassium  ferrocyanide  are  used,  or  gelatin  and  tannic  acid. 
A  thin  film  or  membrane  of  the  precipitate  is  formed  in  the 
wall,  which  is  supported  firmly  by  the  clay,  so  that  large  pres- 
sures can  be  developed  without  destroying  the  membrane.  If 
we  now  fill  the  cup  with  a  solution  of  sugar  or  some  other  solu- 
ble crystalloid,  its  particles  will  bombard  the  walls  of  the  cylin- 
der in  vain  ;  they  cannot  pass  through  the  semipermeable  mem- 
brane. On  the  other  hand,  the  water  can  pass  through,  and  does 
so  in  an  attempt  to  equalize  the  concentration  on  both  sides  of 
the  membrane,  and  hence  the  volume  of  fluid  in  the  cylinder 
increases.  "This  it  will  do  until  the  weight  of  the  column  of  liquid 
in  the  cylinder  balances  the  osmotic  pressure,  and  in  this  way 
we  can  measure  just  how  great  the  pressure  is.  The  amount  of 
pressure  exerted  by  a  substance  in  solution  is  thus  learned  to  be 
very  great;  a  6  per  cent,  solution  of  cane-sugar  produces  a 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL         37 

pressure  of  3075  millimeters  of  mercury  at  14°  (about  sixty 
pounds  to  the  square  inch).  To  produce  osmotic  pressure  it  is 
not  necessary  that  the  membrane  be  absolutely  impermeable  to 
any  of  the  substances — it  may  only  be  relatively  less  permeable 
for  the  solute  than  for  the  solvent.  If,  for  example,  we  fill  a 
parchment  bag  with  concentrated  sugar  solution,  tie  up  the  top 
tightly  and  throw  into  water,  it  will  swell  up  rapidly  and 
eventually  burst.  But  if  the  parchment  is  in  the  form  of  a 
tube,  open  at  the  top,  and  the  lower  end  is  placed  in  water,  the 
amount  of  fluid  inside  the  tube  will  increase  at  first,  but  event- 
ually the  sugar  will  diffuse  out  to  such  an  extent  that  the  solu- 
tion is  of  the  same  concentration  inside  and  outside  of  the  tube, 
and  the  column  of  fluid  will  again  become  of  equal  height  on 
both  sides.  These  results  indicate  that  the  water  passes  through 
the  membrane  more  rapidly  than  does  the  sugar,  but  that  event- 
ually the  sugar  can  all  pass  through. 

Exactly  similar  conditions  exist  in  cells,  particularly  plant 
cells.  The  typical  cell  of  plant  tissues  consists  of  a  cellulose 
wall,  lined  internally  by  a  layer  of  protoplasm  which  inclqses  a 
mass  of  aqueous  solution,  the  cell  sap,  containing  sugar  and 
various  other  solutes.  The  cellulose  wall  is  readily  permeable 
by  water  and  by  most  solutes,  whereas  the  protoplasmic  layer 
inside  it  behaves  like  a  semipermeable  membrane  which  per- 
mits water  to  pass  through  readily  but  hinders  greatly  the  pas- 
sage of  most  solutes  ;  that  it  is  somewhat  permeable  is  attested 
by  the  fact  that  the  cell  sap  contains  solutes  derived  from  the 
external  fluids.  As  a  result  of  this  arrangement  there  is  a  con- 
stant tendency  for  the  cavity  of  the  cell  to  be  distended  by 
water  and  for  the  solutes  within  it  to  exert  their  considerable 
pressure  upon  the  cell  wall.  Because  of  the  strength  of  the 
cellulose  layer  the  cell  can  withstand  great  pressures  that  would 
tear  apart  the  tender  protoplasmic  layer  that  really  determines 
the  osmotic  conditions,  just  as  in  the  experimental  membrane 
the  clay  cylinder  supports  the  delicate  precipitation  membrane. 
It  is  the  osmotic  pressure  that  causes  the  rigidity  or  turgor  of 
plant  cells,  and  explains  the  ability  of  a  tender  green  shoot  to 
hold  itself  upright  or  horizontal  in  the  air ;  and  it  is  the  force 
that  enables  growing  roots  to  lift  great  stones  or  tear  apart 
rocks  in  whose  clefts  they  grow.  If  plant  cells  are  placed  in 
distilled  water,  the  pressure  may  rise  to  such  an  extent  that  the 
cells  burst,  and  it  was  through  studying  this  phenomenon  that 
Pfeffer  worked  out  the  basis  of  our  present  knowledge  of 
osmotic  pressure.  If  the  cell  is  placed  in  a  solution  of  greater 
concentration  than  its  cell  sap,  the  pressure  outside  will  be 


38  INTRODUCTION 

greater  than  that  inside  and  the  protoplasmic  membrane  will  be 
forced  away  from  the  cellulose  wall,  while  its  central  cavity 
shrinks  and  perhaps  disappears  entirely,  the  protoplasm  forming 
a  ball  in  the  center.  This  is  practically  what  occurs  when  a 
plant  stem  is  cut  and  it  "  wilts  " — the  water  is  removed  by  evap- 
oration, the  osmotic  pressure  outside  the  cells  becomes  greater 
than  that  inside,  and  the  water  passes  out.  Likewise  when  a 
plant  cell  dies  the  turgor  is  lost  because  the  membrane  becomes 
permeable,  and  so  pressure  soon  becomes  the  same  on  both  sides 
of  the  cell  wall. 

In  animal  cells  the  wall  is  not  so  highly  developed  as  in 
plants,  nor  is  it  backed  up  by  a  rigid  material  like  cellulose ; 
indeed,  for  many  animal  cells  there  is  no  well-defined  wall  and 
the  protoplasm  appears  to  be  naked.  Nevertheless  the  behavior 
of  the  animal  cells  indicates  that  they  do  possess  what  resembles 
a  cell  wall,  in  that  they  behave  when  in  solutions  as  if  they 
were  surrounded  by  a  diffusion  membrane.  The  degree  to 
which  phenomena  of  this  nature  are  shown  varies  with  different 
cells ;  with  red  corpuscles,  for  example,  the  osmotic  pressure 
influences  are  very  marked,  as  shown  by  the  wrinkling  or 
crenation  of  the  corpuscles  when  they  are  placed  in  fluids  of 
higher  concentration  than  the  blood  plasma,  and  by  their  swell- 
ing and  disintegration  with  escape  of  the  hemoglobin  (hemolysis) 
when  they  are  put  into  distilled  water  or  solutions  of  less  con- 
centration than  the  plasma.  Other  tissue  cells  seem  to  undergo 
more  or  less  alteration  from  changes  in  the  osmotic  pressure  in 
the  fluids  surrounding  them.  The  diffusion  membrane  that 
surrounds  the  cell  is  generally  not  well  defined,  and  for  most 
cells  seems  to  be  but  a  surface  condensation  of  the  protoplasm, 
perhaps  formed  through  the  effects  of  surface  tension.  The 
diffusion  within  the  cell,  however,  seems  to  be  so  much  more  free 
than  it  is  through  the  cell  wall  that  it  is  probable  that  the  sur- 
face layer  of  the  cell  is  quite  different  from  that  of  the  rest  of 
the  cytoplasm.  It  seems  probable  that  this  surface  diffusion 
membrane  contains  a  large  proportion  of  cell  lipoids,  i.  e., 
cholesterin  and  lecithin  (for  the  red  corpuscles  this  is  practically 
certain) ;  hence  substances  soluble  in  lipoids  penetrate  the  cell 
readily,  while  to  substances  insoluble  in  lipoids  the  cell  is  nearly 
or  quite  impermeable  (Overton).  Probably  the  wall  of  the 
animal  cell  is  not  so  nearly  semipermeable  as  is  that  of  the 
plant  cell,  for  nowhere  in  the  animal  body  do  we  get  such 
turgor  in  the  cells  as  we  see  in  plant  tissues.  Lacking  a  cellu- 
lose wall,  animal  cells  could  not  develop  such  an  internal 
pressure  without  rupturing,  and  such  a  process  of  rupturing 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL         39 

(plasmorrhexis,  plasmoptysis)  does  not  seem  to  be  a  normal  occur- 
rence in  animal  tissues.  We  shall  be  most  nearly  correct, 
probably,  if  we  look  upon  the  animal  cell  as  possessing  a  deli- 
cate diffusion  membrane  at  its  surface,  through  which  water 
passes  more  readily  than  do  most  crystalloids,  and  through 
which  colloids  pass  almost  not  at  all,  but  the  exclusion  of  each 
of  these  types  of  substances  is  merely  relative  and  not  abso- 
lute. 

Since  osmotic  pressure,  exactly  like  gas  pressure,  is  produced 
by  the  bombarding  of  the  walls  of  the  container  by  particles  in 
the  solution,  the  amount  of  pressure  will  vary  in  proportion  to 
the  number  of  particles  present.  With  such  substances  as 
sugar  and  urea,  the  non-electrolytes,  the  moving  particles  seem 
to  be  molecules,  and  so  a  solution  of  sugar  or  urea  will  produce 
an  osmotic  pressure  directly  proportional  to  the  number  of 
molecules  it  contains.  In  the  case  of  the  electrolytes,  however, 
the  ions  produce  pressure  as  well  as  the  molecules,  and  hence 
an  electrolyte  in  solution  will  produce  a  relatively  high  osmotic 
pressure  as  compared  with  an  equivalent  solution  of  a  non- 
electrolyte,  since  each  molecule  yields  two  or  more  ions.  Col- 
loids, however,  exert  so  slight  an  osmotic  pressure  that  it  is 
difficult  of  detection;  this  probably  depends  on  the  great  size 
and  slight  motility  of  their  molecules.  In  the  many  and 
important  osmotic  processes  of  the  animal  organism,  therefore, 
the  colloids  take  no  part  except  in  helping  to  form  the  diffusion 
membrane,  and  in  preventing  the  diffusion  of  one  another.  It 
is  interesting  to  consider  also  that  colloids  under  ordinary  con- 
ditions do  not  greatly  modify  the  diffusion  of  crystalloids 
through  a  solution  containing  both  classes  of  matter.  The  fact 
that  a  cell  is  full  of  dissolved  colloids  does  not  seriously  affect 
the  osmotic  properties  of  the  intracellular  crystalloids,  provided 
it  is  not  condensed  in  such  a  way  as  to  form  diffusion  mem- 
branes. But  as  all  the  cleavage  products  of  proteids  after  they 
have  passed  the  peptone  stage  are  crystalloids  (e.  g.,  leucin, 
tyrosin,  glycocoll,  etc.),  by  decomposition  of  the  intracellular 
proteids  the  osmotic  pressure  may  be  greatly  raised.  As  long 
as  the  cell  is  living  there  can  be  no  constancy  in  composition, 
for  metabolic  processes,  by  producing  from  proteids  that  have 
no  osmotic  pressure  crystalloidal  substances  that  do  have 
osmotic  pressure,  cause  intracellular  osmotic  conditions  to  be 
continually  varying.  As  a  result,  streams  of  diffusing  parti- 
cles are  moving  about  in  every  direction,  setting  up  new 
chemical  reactions  and  consequent  new  osmotic  currents.  The 
greater  the  difference  in  osmotic  pressure  between  a  cell  and  its 


40  INTR  OD  UCTION 

environs,  and  between  the  different  parts  of  the  same  cell,  the 
more  powerful  the  osmotic  effects,  and  as  a  result  the  greater 
the  capacity  for  accomplishing  work.  The  storing  up  of  insolu- 
ble and  indiffusible  forms  of  substance,  such  as  glycogen,  fat, 
and  proteids,  is  an  important  factor  in  maintaining  inequali- 
ties in  osmotic  pressure,  and  in  this  way  of  increasing  work 
capacity.1 

The  relation  of  osmotic  pressure  and  osmosis  to  physiological 
problems  is  only  beginning  to  be  studied.  It  is  apparent  that 
they  must  be  of  essential  importance  in  absorption  from  the 
alimentary  canal,  in  absorption  and  excretion  between  the  cells 
and  the  blood  stream,  and  in  secretion  by  glandular  organs ; 
but  it  is  also  certain  that  they  are  no  less  important  in  all  the 
less  obvious  chemical  and  physical  processes  of  the  cell.  These 
matters  will  not  be  discussed  here  at  length.2  In  pathological 
processes  osmotic  pressure  may  play  an  equally  important  role, 
and  the  facts  discussed  in  the  preceding  paragraphs  will  be 
alluded  to  frequently  in  subsequent  chapters. 

COLLOIDS  3 

Since  Graham  in  1861  studied  the  differences  between  the 
substances  that  did  or  did  not  diffuse  readily  through  animal  or 
parchment  membranes,  soluble  substances  have  been  classified 
in  the  two  main  groups  of  colloids  and  crystalloids,  which  dis- 
tinction Graham  believed  separated  two  entirely  different  classes 

1  J.    Traube  has  developed  a  theory  of  osmosis,  depending  upon  surface  ten- 
sion which  appears  to  be  of  much  importance  (Zeit.  f.  exper.  Path.  u.  Ther. ; 
1905  (2),  117).      According  to  this  theory  the  direction  and  speed  of  osmosis 
are  determined  by  the  difference  in  surface  tension  between  the  fluids  on  the 
two  sides  of  a  membrane,  the  fluid  with  the  less  surface  tension  passing  towards 
the  one  with  the  higher  tension.     Surface  tension  differs  from  osmotic  pressure 
especially  in  that  the  nature  of  the  dissolved  substance  is  of  more  importance 
than  the  quantity,  e.  g.,  1  gmw.  of  arnyl  alcohol  lowers  surface  tension  as  much 
as  81  gmw.  of  methyl  alcohol,  although  equivalent  amounts  of  both  produce 
the  same  effect  on  osmotic  pressure.    On  this  theory  is  built  up  a  conception  of 
physiological  secretion  and  absorption,  which  considers  that  only  fluids  of  lower 
tension   than  that  of  the  blood  enter  it,  e.  g.,  absorption  from  the  gastrointes- 
tinal tract  is  favored  because  bile  and  peptone  both  lower  surface  tension,  etc. 
For  details  see  the  original  article  cited. 

2  For  further  consideration  of  the  subject  of  osmotic  pressure  in  these  rela- 
tions see  :  Livingston,  "  The  Role  of  Diffusion  and  Osmotic  Pressure  in  Plants," 
University  of  Chicago  Press,  Chicago,  1903  ;  Czapek,   "  Biochemie  der  Pflan- 
zen,"  Jena,  1903.     Also,  Hober,  Cohen,  and  Hamburger,  all  previously  cited. 

3  For  full  discussions  of  the  nature  of  colloids  see :  Hober,  u  Physikalische 
Chemie  der  Zelle,"  Leipzig,  1902 ;  Pauli,  Ergebnisse  der  Physiologic,  1904 
(III,  Abt.  1),  155;  Mann,  "Physiological  Histology,"  Oxford,  1902.      The 
complete  literature  is  collected  and  summarized  by  Aron  in  the  Biochem- 
isches  Centralblatt,  1905  (3),  pages  461  and  501.      The  relation  of  colloids  to 
the  problems  of  immunity  is  reviewed  by  Zangger,  Cent.  f.  Bakt.  (ref.),19Q5 
(36),  161. 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL        41 

of  matter.  Although  at  the  present  time  the  differences  between 
the  two  classes  do  not  seem  so  great,  yet  the  same  division  is 
found  useful  in  classification.  By  colloids  Graham  indicated 
those  substances  which  were  dissolved  to  the  extent  of  showing 
no  visible  particles  in  suspension,  but  which  either  did  not  pass 
through  diffusion  membranes  at  all,  or  did  so  very  slowly 
indeed,  as  compared  to  the  crystalloid  substances.  Under  cer- 
tain conditions  they  tended  to  assume  a  sticky,  glue-like  nature, 
hence  the  name.  (Many  substances  are  now  known  which 
have  the  chief  properties  of  the  colloids  and  are  therefore  clas- 
sified among  them,  but  never  are  glue-like,  e.  g.,  the  colloidal 
metals,  so  that  the  name  has  lost  some  of  its  original  signifi- 
cance.) The  physical  property  which  Graham  particularly  noted 
in  the  colloids,  besides  their  non-diffusibility,  was  the  tendency 
to  assume  various  states  of  solidity.  Not  only  can  they  be  in 
solution,  when  he  called  them  "  sols "  (when  the  solvent  was 
water,  "  hydrosols  "),  but  they  can  become  quite  firm  although 
containing  much  water  (then  called  "  gels  "  or  "  hydrogels  "). 
The  gels  may  assume  a  firm,  coagulated  condition,  the  so-called 
"  pectous  "  state,  which  state  is  permanent  in  that  the  gel  form 
cannot  be  reobtained  from  the  pectous  modification.  Finally 
the  colloid  can  be  in  a  dry,  solid  state,  quite  free  from  water, 
and  then  not  a  sol  at  all. 

Included  in  the  great  class  of  colloids  are  all  forms  of  pro- 
teids,  and  also  gums,  starch,  dextrin,  glycogen,  tannin,  chondrin, 
perhaps  the  soaps  and  lecithin,  probably  the  enzymes,  and  also 
the  greater  number  of  organic  dyes ;  also  there  are  inorganic 
colloids,  such  as  silicic  acid,  arsenic  sulphide,  hydrated  oxide 
of  iron,  and  many  other  similar  compounds,  besides  the  elements 
themselves,  especially  the  noble  metals  which  may  exist  in  col- 
loidal form.  It  will  be  seen  at  once  that  the  chief  constituents 
of  the  cells,  in  fact  nearly  all  the  primary  constituents  except  the 
inorganic  salts,  are  organic  colloids,  and  therefore  the  properties 
of  the  cells  are  largely  dependent  upon  the  properties  of  the  colloids. 

In  considering  the  characteristics  of  the  colloids  we  at  once 
meet  the  question — What  distinguishes  the  colloids  from  the 
crystalloids,  on  the  one  side,  and  from  suspensions  or  emulsions 
on  the  other  ?  An  enormous  mass  of  literature  has  been  piled 
up  by  the  workers  upon  the  problems  here  presented,  and 
although  the  last  word  has  not  been  said,  yet  a  fair  understand- 
ing of  the  conditions  of  solution  has  been  reached,  and  many 
important  properties  have  been  discovered  and  explained.  The 
sum  and  substance  of  our  present  conception  of  the  nature  of 
colloidal  solution  may  be  briefly  summarized  as  follows : 


42  INTRODUCTION 

It  is  possible  for  solid  substances  to  be  so  divided  among  the 
particles  of  a  solvent  that  they  remain  permanently  in  this 
condition,  neither  aggregating  into  masses  nor  separating  out 
through  the  action  of  gravity.  With  some  substances,  as  sugar, 
for  example,  the  solid  seems  to  divide  up  into  its  molecular 
form,  each  molecule  being  free  from  all  others  of  its  kind 
except  during  occasional  contacts.  Some  other  substances,  as 
salt,  go  still  further,  and  the  molecule  divides  into  two  or  more 
parts,  which  have  different  electric  charges  (ionization).  The 
first  of  these  classes  of  substances  forms  a  solution  which  con- 
tains no  particles  visible  by  any  known  means,  does  not  contain 
particles  large  enough  to  refract  or  reflect  light  impinging  upon 
them,  exerts  a  large  osmotic  pressure,  but  does  not  concluct 
electricity.  The  other,  in  which  ionization  has  occurred,  differs 
solely  in  its  capacity  to  conduct  electricity  readily.  Both  are 
true  solutions  of  crystalloids ;  the  one  which  does  not  ionize  is  a 
non-electrolyte  ;  the  other,  by  virtue  of  its  ionization,  is  an  electro- 
lyte,  the  ions  carrying  electric  charges  through  the  solution. 

At  the  other  end  of  the  scale  we  have  substances  which  are 
quite  insoluble  when  in  masses,  but  which,  when  very  finely 
divided  by  mechanical  means,  can  be  suspended  and  uniformly 
distributed  through  a  fluid  without  having  any  marked  tendency 
to  aggregate  or  settle  out.  Such  suspensions  or  emulsions  con- 
tain particles  visible  under  the  microscope,  usually  appear 
turbid,  refract  light,  are  non-diffusible,  exert  no  osmotic 
pressure,  and  do  not  transmit  electricity.  Such  mixtures  are 
obviously  very  different  from  the  true  solutions  above  described. 

Between  these  two  extremes  stand  the  colloids,  which  vary 
in  their  properties  so  that  they  approach  sometimes  the  suspen- 
sions (e.  g.j  lecithin,  or  coagulated  egg-albumin  in  colloidal  sus- 
pension), and  sometimes  more  nearly  the  true  solutions  (e.  g., 
dextrin).  No  sharp  boundaries  can  be  drawn  between  any  of 
the  members  of  the  series.  Indeed,  one  substance  may  present 
all  the  different  stages  under  different  conditions ;  to  illus- 
trate, arsenic  sulphide  may  appear  as  a  suspension  in  water, 
with  such  large  aggregations  of  its  particles  that  most  or  all  of 
it  can  be  removed  by  an  ordinary  filter.  It  may  exist,  how- 
ever, in  the  form  of  a  colloidal  solution  or  suspension,  which 
appears  perfectly  homogeneous  to  the  naked  eye,  but  when 
placed  under  the  microscope,  the  fluid  is  found  to  be  filled  with 
minute  particles  in  Brownian  movement.  Still  other  colloidal 
suspensions  of  the  same  substance  may  be  obtained  which  with 
the  best  oil-immersion  lenses  show  no  particles  of  any  kind, 
but  when  these  solutions  have  a  beam  of  light  passed  through 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL        43 

them  it  becomes  visible  because  of  the  reflection  of  the  light 
waves  on  the  surfaces  of  solid  particles  that  are  suspended  in 
the  fluid,  as  a  ray  of  sunlight  becomes  visible  in  a  dusty  room 
(TyndalPs  phenomenon l ).  Hence  this  solution,  which  even 
with  the  microscope  appears  as  perfectly  homogeneous  as  a  salt 
solution,  is  in  reality  full  of  solid  particles.  Finally,  still  other 
solutions  of  arsenic  sulphide  may  be  obtained  in  which  the 
particles  are  so  fine  as  to  diffuse  like  an  ordinary  solution  of  a 
crystalloid. 

In  a  similar  manner  various  other  colloids  may  be  found  to 
show  different  characters,  some  agreeing  with  the  properties  of 
the  typical  suspensions,  and  some  with  the  properties  of  the 
true  solutions.  They  stand  in  an  intermediary  position,  differ- 
ing quantitatively  in  one  way  or  another  from  the  true  solu- 
tions, but  yet  approaching  them  closely  and  sometimes  almost 
indistinguishably  resembling  them.  For  the  most  part,  how- 
ever, the  colloids  show  characteristics  decided  enough  to  entitle 
them  to  separate  classification,  and  to  make  any  confusion  with 
the  crystalloids  impossible. 

The  Characteristics  of  Colloids. — The  chief  properties 
of  the  colloids  are,  then,  as  follows  : 

Amorphous  Form. — This,  like  almost  all  other  "colloidal 
properties/7  is  not  absolute,  for  in  egg-albumin,  hemoglobin, 
and  various  globulins  we  have  proteids  which  in  every  respect 
are  typical  colloids,  yet  they  form  crystals  readily  and  abun- 
dantly. Oxyhemoglobin,  the  molecular  weight  of  which  is 
calculated  at  about  14,000,  exhibits  TyndalPs  phenomenon, 
and  will  not  pass  through  a  very  fine  porcelain  filter,  and  there- 
fore resembles  the  colloids  decidedly,  yet  it  forms  beautiful 
crystals.  The  very  fact  that  crystals  are  formed,  Spiro  points 
out,  is  proof  that  when  in  solution  the  individual  molecules  must 
have  been  free  and  separate,  for  otherwise  they  could  scarcely 
unite  in  the  definite  spatial  relations  necessary  to  produce 
crystalline  forms.2 

1  The  so-called  ultra-microscopic  method  of  studying  minute  particles,  devised 
by  Siedentopf  and  Zsigmondy,  depends  upon  the  same  phenomenon.     In  this 
method  the  particles  are  illuminated  in  the  microscopic  field  by  an  intense  ray 
of  light,  and  the  reflection  of  light  causes  the  particles  to  appear  as  minute 
luminous  points.     Particles  as  small  as  0.005  //  can  be  detected  in  this  way,  and 
ordinary  colloidal  solutions  of  albumin  appear  filled  with  moving  particles. 

2  This  indicates  that  in  colloidal  solutions  the  molecules  may  be  free,  and 
not  necessarily   aggregates.     This  is  perhaps  only  true  for  the  substances  of 
very  great  molecular  dimensions,  such  as  the  proteids ;  the  colloidal  solutions 
of  substances  with  smaller  molecules  having  the  molecules  united  in  large 
groups.     On  this  basis  the  essential  difference  between  colloidal  and  true  solu- 
tions is  merely  one  of  the  size  of  the  free  particles. 


44  INTRODUCTION 

Graham's  term  of  "  crystalloid/'  therefore,  does  not  strictly 
express  the  distinction  he  intended,  or,  rather,  the  distinction  he 
intended  does  not  exist  in  so  decided  a  way  as  he  imagined. 
With  these  few  exceptions,  however,  the  colloids  do  not  present 
any  typical  structure,  and  are  not  crystalline  under  any  visible 
condition.  But  when  they  are  made  insoluble  by  chemical 
means  they  may,  under  certain  conditions,  produce  rather 
characteristic  non-crystalline  structures,  a  matter  that  will  be 
discussed  in  a  subsequent  paragraph. 

Solubility. — Although  we  speak  of  "  colloidal  solutions,  " 
this  term  does  not  commit  us  to  the  theory  of  the  identity  of 
the  solution  of  colloids  with  that  of  crystalloids.  We  have 
above  stated  what  seems  to  be  a  fair  view  of  the  matter  as 
shown  by  many  methods  of  experimentation.  Most  colloids 
seem  to  be,  in  fact,  suspensions  of  masses  of  molecules,  or  per- 
haps of  very  large  single  molecules,  and  a  true  solution  is  like- 
wise a  suspension  of  single  molecules  or  of  ions.  When  the 
aggregations  of  molecules  are  sufficiently  large,  we  have  an 
ordinary  suspension  ;  but  a  single  proteid  molecule  is  as  large 
as  a  very  great  number  of  molecules  of  such  substances  as 
sugar  (crystalloid)  ;  or  tannin,  C14H10O9  (colloid) ;  or  calcium 
carbonate  (insoluble,  suspension)  ;  and  it  would  be  strange  if  a 
true  solution  of  a  proteid  did  not  behave  in  many  particulars 
like  a  suspension  of  molecular  aggregates  of  dimensions  simi- 
lar to  the  dimensions  of  proteid  molecules.  Nearly  all  col- 
loidal solutions  show  TyndalPs  phenomenon,  which  demon- 
strates the  existence  of  particles  in  suspension  large  enough  to 
reflect  light  from  their  surfaces.  Most  of  the  colloids  are  held 
back  by  very  fine  filters  to  a  greater  or  less  degree ;  some  are 
almost  entirely  retained  by  a  hardened  paper  filter,  while  others 
pass  through  the  finest-pored  clay  filters.  Furthermore,  the 
metallic  colloids,  such  as  those  of  platinum,  gold,  and  silver, 
are  unquestionably  suspensions  of  finely  divided  particles  of 
metal,  yet  they  exhibit  all  the  typical  phenomena  of  colloids, 
passing  through  many  sorts  of  filters,  and  even  accomplishing 
the  same  hydrolytic  changes  as  many  enzymes. 

It  must  also  be  mentioned  that  the  solvent  is  probably  an 
important  factor  in  determining  the  colloidal  or  non-colloidal 
nature  of  a  substance ;  e.  g.,  soaps  form  true  solutions  in  alco- 
hol and  colloidal  solutions  in  water ;  gelatin  forms  colloidal 
solutions  in  water  but  not  in  ether,  whereas  rubber  forms  col- 
loidal solutions  in  ether  but  not  in  water. 

Closely  related  to  solubility  is  the  phenomenon  of  imbibition 
(the  "  Quellung  "  of  German  writers),  which  may  be  defined  as 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL         45 

the  taking  up  of  a  fluid  by  a  solid  body  without  chemical 
change.  Not  all  colloids  possess  this  property,  but  it  is  shown 
by  most  of  the  organic  colloids,  particularly  the  proteids.  Fick 
distinguishes  capillary,  osmotic,  and  molecular  imbibition,  the 
latter  of  which  is  the  form  exhibited  by  colloids,  and  it  occurs 
independent  of  the  existence  of  pores  or  other  preformed  spaces 
in  the  imbibing  body.  The  imbibition  of  water  by  colloids  is 
more  than  a  simple  mechanical  process,  for  it  is  accompanied 
by  a  contraction  in  the  total  volume  of  solid  and  water,  and  by 
the  evolution  of  heat.  On  the  other  hand,  the  physical  proper- 
ties of  an  aqueous  colloidal  solution  show  that  the  colloid  is 
not  chemically  combined  in  the  form  of  a  hydrate.  To  describe 
this  peculiar  relation  Hofmeister  and  Oswald  recommend  the 
term  "  mechanical  affinity.  "  Hardy  has  shown  that  water 
held  in  a  gelatin  jelly  cannot  be  removed  by  great  pressures 
(400  pounds  to  the  square  inch),  but  after  the  nature  of  the 
jelly  is  so  changed  by  formalin  that  it  is  no  more  liquefiable  by 
heat,  the  water  can  be  easily  expressed  from  the  loose  meshwork 
that  is  formed.  It  would  seem  from  this  that  the  imbibition 
and  retention  of  water  by  colloids  may  be  closely  related  to 
surface  phenomena.  Hofmeister  has  shown  that  organized 
animal  tissues  obey  the  same  laws  of  imbibition  as  do  simple 
gelatin  plates,  and  probably  this  phenomenon  of  colloids  is 
very  important  in  physiological  processes. 

Non=diffusibility. — The  lack  of  power  to  pass  through 
animal  and  parchment  membranes,  which  was  Graham's  start- 
ing-point in  the  study  of  colloids,  is  also  only  a  relative  condi- 
tion. This  is  shown  by  the  following  figures  giving  the  relative 
time  required  by  the  same  amount  of  different  substances  to 
pass  through  a  certain  diffusion  membrane  : 

Sodium  chloride 2.33 

Sugar  (< 7.00 

Magnesium  sulphate 7.00 

Proteid 49.00 

Caramel , 98.00 

This  difference  of  time  is  so  great,  however,  as  to  permit  of 
separation  of  salts  from  proteids,  etc.,  by  dialyzation,  a  process 
in  constant  use.  Primarily  the  ability  to  diffuse  through  a 
given  membrane  requires  that  the  diffusing  substance  be  soluble 
in  the  membrane.  Diffusion  membranes  are  always  composed 
of  colloids,  e.  g.,  animal  bladders,  or  parchment,  which  is  a  col- 
loidal cellulose.  Crystalloids  are  generally  soluble  in  colloids, 
while  colloids  are  little  or  not  at  all  soluble  in  other  colloids, 
and  hence  do  not  diffuse  through  one  another  and  therefore  they 


46  INTRODUCTION 

cannot  permeate  diffusion  membranes.  For  example,  if  a  stick 
of  agar  jelly  be  placed  in  a  solution  of  ammoniated  copper  sul- 
phate (a  crystalloid),  and  another  be  placed  in  *a  solution  of 
Prussian  blue  (a  colloid),  it  will  be  found  that  the  copper  solu- 
tion penetrates  the  agar  rapidly,  while  the  colloidal  solution  of 
Prussian  blue  does  not  penetrate  it  at  all.  This  property  is  of 
great  importance,  undoubtedly,  in  keeping  different  colloidal 
constituents  of  the  cell  in  given  localities  within  its  protoplasm, 
e.  g.y  the  oxidizing  ferments  seem  to  be  chiefly  localized  within 
the  nucleus  ;  the  colloidal  glycogen  remains  where  it  is  formed 
in  the  cytoplasm,  unable  to  escape  from  the  cell,  whereas  the 
crystalloidal  sugar  from  which  it  is  formed  and  into  which  it  is 
converted,  diffuses  rapidly  into  or  out  of  the  cell. 

The  osmotic  pressure  of  the  colloids  is  so  small  that 
some  investigators  doubt  that  colloids  really  do  exert  any 
osmotic  pressure  by  themselves.  They  would  explain  such 
small  positive  results  as  have  been  obtained  by  assuming  the 
presence  of  contaminating  substances,  a  criticism  that  is  well 
grounded  on  the  fact  of  the  extreme  difficulty  of  obtaining  col- 
loids in  a  pure  state.  The  closely  related  phenomena  of  diffu- 
sion, depression  of  freezing-point,  and  elevation  of  boiling-pointy 
are  also  exhibited  by  colloids  to  but  an  extremely  slight  degree. 
For  example,  in  one  experiment,  the  dissolving  of  from  14  per 
cent,  to  44  per  cent,  of  egg-albumin  in  water  lowered  the  freez- 
ing-point but  0.02°  to  0.06°  ;  and  some  other  colloids  have 
even  less  effect.  But  the  results  of  the  latest  and  best  experi- 
ments seem  to  indicate  that  the  trifling  effects  of  colloids  upon 
osmotic  pressure  and  upon  freezing-  and  boiling-points  observed 
in  colloidal  solutions  are  due  to  the  colloids  themselves,  although 
it  may  possibly  be  that  some  of  these  effects  are  due  to  the 
high  surface  tension  and  cohesion  affinity  of  the  colloids.  In 
all  cellular  processes  accompanied  by  manifestations  of  osmotic 
pressure  or  diffusion,  however,  the  crystalloids  may  be  consid- 
ered as  almost  entirely  responsible. 

Electrical  Phenomena. — As  colloids  do  not  separate  freely 
into  ions  when  dissolved,  they  do  not  conduct  electricity  appre- 
ciably. However,  when  an  electric  current  is  passed  through 
water  containing  colloids  in  solution,  the  colloidal  particles  tend 
to  pass  to  one  pole  or  the  other.  Most  colloids  move  toward 
the  anode.  This  phenomenon,  cataphoresis,  is  also  generally 
exhibited  by  suspensions,  and  hence  in  this  particular  the  colloids 
resemble  suspensions  rather  than  solutions.  Helmholtz  has 
explained  the  movement  of  the  suspended  particles  as  due  to 
the  accumulation  of  electrical  charges  upon  the  surfaces  of  two 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL        47 

heterogeneous  media  when  in  contact.  The  nature  of  the  charge 
depends  upon  both  the  suspended  substance  and  the  fluid  ;  e.  g., 
sulphur  or  graphite  particles  suspended  in  water  assume  a  nega- 
tive charge  and  move  toward  the  anode,  but  when  suspended 
in  oil  of  turpentine  they  become  positively  charged  and  move 
toward  the  cathode.  Water  has  such  a  high  dielectric  constant 
that  most  substances  in  water  become  negatively  charged  as  com- 
pared with  the  water,  and  move  toward  the  positive  pole  or 
anode. 

Hardy  has  observed  that  colloidal  solutions  of  coagulated 
proteids  move  toward  the  anode  when  in  alkaline  solution,  and 
toward  the  cathode  when  in  acid  solution.  This  peculiar  prop- 
erty of  proteids  suggests  that  perhaps  simple  surface  phenom- 
ena do  not  suffice  to  account  for  the  electrification  of  all  colloid 
particles.  Knowing  the  peculiar  amphoteric  character  of  pro- 
teids, which  is  probably  due  to  the  presence  of  both  NH2  and 
COOH  groups  in  the  molecule,  we  can  readily  believe  that  in 
an  acid  solution  the  NH2  radicles  are  combined  with  the  acid, 
leaving  the  COOH  radicles  free.  The  molecule  would  then  have 
acid  properties,  and  could  dissociate  into  an  acid  H  ion  and  a 
basic  or  electrically  positive  colloid  ion.  The  colloid  ion  would 
then  go  toward  the  negative  pole  slowly,  because  of  its  great 
size.  Were  this  true,  however,  we  might  expect  the  colloidal 
solutions  to  show  more  conductivity  than  they  do,  but  possibly 
on  account  of  the  very  large  size  of  the  proteid  molecule  too 
few  H  ions  are  liberated  to  produce  much  effect,  and  also,  ioni- 
zation  may  be  much  less  in  a  neutral  solution  than  in  an  acid  or 
alkaline  one.  Electrification  of  suspensions  of  platinum,  gold, 
or  powdered  glass  could  hardly  be  explained  on  this  basis,  unless 
we  assume  that  the  water  or  other  solvent  united  with  the  par- 
ticles becomes  ionized.  Quite  possibly  we  have  both  ionization 
and  cataphoresis  occurring,  the  former  in  the  case  of  some  com- 
pounds, the  last  in  the  case  of  elements  or  perfectly  insoluble 
substances  held  in  suspension. 

Surface  tension,  which  may  be  described  as  the  force  with 
which  a  fluid  is  striving  to  reduce  its  free  surface  to  a  minimum,  is 
highly  exhibited  by  colloids  as  compared  with  crystalloids.  The 
phenomenon  of  cataphoresis  depends  upon  the  existence  of  a  high 
surface  tension,  and  it  is  this  same  property  that  explains  the 
ability  of  colloidal  particles  to  stay  suspended  in  a  fluid  which 
has  a  much  lower  specific  gravity  than  the  solid.  The  forma- 
tion of  emulsions  and  the  spreading  out  of  oil  upon  the  surface 
of  water  also  depend  upon  surface  tension.  Ameboid  move- 
ment may  be  attributed  to  changes  in  surface  tension,  as  also 


48  INTR  OD  UCTION 

may  phagocytosis.  (The  relation  of  surface  tension  to  these 
processes  will  be  considered  under  the  subject  of  Inflammation.) 

The  effect  of  colloids  upon  chemical  processes 
going  on  within  their  solutions  or  gels  is  surprisingly  small. 
Salts  in  solution  in  a  thick  gel  of  agar  or  gelatin  will  diffuse 
almost  as  rapidly  as  in  water ; l  they  will  also  ionize  as  rapidly 
as  in  watery  solutions,  and  chemical  reactions  occur  with  the 
same  speed  and  completeness  as  if  the  colloids  were  absent. 
Furthermore  it  makes  little  difference  whether  these  processes 
are  measured  in  a  colloid  solution  that  is  liquid,  or  after  it  has  set 
in  the  gel  form.  These  facts  merely  indicate  that  the  colloids 
do  not  greatly  impede  the  movements  of  molecules  or  ions  in 
solutions.  On  the  other  hand,  as  before  mentioned,  colloids 
diffuse  little  or  not  at  all  into  each  other.  Hence,  in  the  cell 
the  colloids  are  quite  fixed  in  their  positions,  whereas  the  crys- 
talloids may  wander  about  freely,  and  this  arrangement  is  cer- 
tainly of  great  importance  in  biologic  processes.  Pauli  suggests 
the  probability  that  the  fixation  of  the  colloid  causes  the  cell 
to  have  different  properties  in  different  parts,  and  so  various 
reactions  may  occur  independently  in  different  areas  of  the  cyto- 
plasm. The  possibility  of  the  correctness  of  this  view  is 
increased  when  we  consider  that  the  enzymes  are  colloids,  for 
there  is  much  evidence  to  show  that  they  are  distributed  in  just 
such  an  uneven  manner  within  the  cells. 

Although  colloids  permit  the  passage  of  dissolved  crystalloids 
through  them,  they  greatly  interfere  with  the  movement  of 
larger  particles.  This  property  accounts  for  the  ability  of 
colloids  to  hold  many  insoluble  substances  in  such  extremely 
fine  suspensions  that  they  seem  superficially  to  be  in  true  solu- 
tion. If,  for  example,  phosphoric  acid  is  added  to  a  solution  of 
casein  in  lime-water,  the  calcium  phosphate  formed  does  not 
precipitate.  It  is  not  in  solution,  however,  but  rather  exists  as 
a  suspension  of  very  finely  divided  particles  of  the  salt  which 
the  colloid  keeps  from  aggregating  into  particles  large  enough 
to  be  visible  or  to  overcome  the  viscosity  of  the  fluid  and  sink 
to  the  bottom.  Probably  in  this  way  many  substances,  includ- 
ing calcium  salts,  are  carried  in  the  blood,  held  in  permanent 
suspension  by  the  proteids.  Substances  thus  finely  divided 
will  have  extremely  large  surface  area  for  reactions,  and,  there- 
fore, will  undoubtedly  undergo  changes  with  considerable  rapid- 
ity and  facility,  although  not  in  solution. 

1  The  retarding  influence  of  colloids  upon  diffusion  has,  however,  been  gen- 
erally underestimated,  according  to  the  most  recent  researches.  (See  Meyer, 
Hofmeister's  Beitr.,  1905  (8),"  393;  Nell,  Ann.  d.  Phys.,  1905  (18),  323; 
Flexner  and  Noguchi,  Amer.  Med.,  1906  (1),  154.) 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL        49 

Precipitation  and  Coagulation  of  Colloids. — Be- 
cause of  the  rather  slender  margin  by  which  the  colloids  are 
separated  from  the  suspensions,  their  persistence  in  solution  is 
generally  in  a  rather  precarious  condition.  Relatively  slight 
changes  suffice  to  throw  the  colloids  out  of  solution,  and  when 
once  precipitated,  they  are  often  incapable  of  again  dissolving  in 
the  same  solvent.  Solutions  of  albumin  may  undergo  sponta- 
neous coagulation  on  standing  for  some  time,  and  agitation 
rapidly  produces  the  same  effect  in  many  proteid  solutions. 
Some  inorganic  colloids  are  as  readily  coagulated  as  the  proteids. 
A  comparatively  small  rise  in  temperature,  less  than  to  50 °C. 
with  some  proteids,  renders  the  proteid  perfectly  insoluble. 
Furthermore,  we  have  coagulation  of  proteid  solutions  by  enzyme 
action.  The  inorganic  "  colloidal  suspensions  "  may  be  precipi- 
tated by  the  addition  of  very  small  quantities  of  electrolytes. 
Colloidal  solutions  of  the  type  of  the  proteids  are  not  so  read- 
ily precipitated  by  most  electrolytes,  but  if  to  the  solution  large 
quantities  of  crystalloids  are  added,  the  proteid  molecules  are 
practically  crowded  out  of  solution,  as  in  the  "  salting-out " 
process  used  in  separating  proteids  by  ammonium  sulphate  and 
other  salts.  The  effect  of  heat  upon  different  colloids  is  pecu- 
liar, in  that  some  varieties,  as  silicic  acid,  aluminium  hydrate, 
and  many  proteids  are  rendered  so  insoluble  that  they  cannot 
again  be  dissolved  in  any  fluid  without  first  being  modified  in 
some  way  ;  whereas  colloids  of  the  type  of  gelatin  and  agar  are 
made  more  soluble  by  heat.  The  change  of  colloids  into  insolu- 
ble forms,  the  "  peetous "  condition  of  Graham,  requires  the 
presence  of  water,  for  the  dry  colloids  may  be  heated  to  rela- 
tively high  temperatures  without  losing  their  solubility.  On 
the  other  hand,  dehydration  of  colloids  while  in  solution  will 
result  in  their  precipitation  and  coagulation,  as  occurs  in  proteid 
solutions  when  alcohol  is  added. 

Colloids  are  precipitated  by  many  electrolytes,  apparently 
through  the  formation  of  true  ion  compounds,  one  or  both  of 
the  ions  of  the  electrolytes  uniting  with  the  colloid  ion  ;  although 
some  writers,  as  Spiro,  believe  that  the  combination  is  merely 
an  additive  one  between  entire  molecules.  Mathews l  has 
advanced  the  theory  that  the  solution  tension  of  the  salts  is  the 
chief  factor  in  determining  the  precipitation  of  colloids  by  elec- 
trolytes. Colloidal  particles  have  a  high  surface  tension  which 
is  always  tending  to  reduce  the  volume  of  the  particle,  and  in 
colloidal  solutions  this  is  constantly  opposed  by  the  force  of 
solution  tension.  If  the  solution  tension  of  the  salt  is  of  such 
1  American  Journal  of  Physiology,  1905  (14),  203. 


50  INTRODUCTION 

a  charge  as  to  increase  the  solution  tension  of  the  colloid,  the 
solubility  of  the  colloid  is  increased,  but  if  it  is  of  opposite 
charge  to  that  of  the  colloid,  the  surface  tension  is  no  longer 
counterbalanced  by  the  solution  tension,  and  the  bulk  of  the 
molecule  is  reduced,  while  its  weight  remains  the  same  ;  hence  it 
falls  out  of  the  solution.  A  similar  effect  may  be  produced  by 
the  union  of  several  molecules  by  a  polyvalent  ion — their  total 
surfaces  will  then  be  much  reduced  as  compared  with  what  it 
was  when  they  were  separate,  and  so  the  surface  energy  is  no 
longer  sufficient  to  keep  them  in  solution.  In  general,  precipi- 
tation of  colloids  results  from  the  reduction  of  the  surface  in 
proportion  to  the  mass,  because  of  an  aggregation  of  the  particles  ; 
this  may  be  brought  about  by  changing  the  surface  electrical 
conditions,  by  uniting  the  molecules  chemically,  or  by  reducing 
the  amount  of  the  solvent. 

The  Structure  of  Colloids  and  of  Protoplasm. — Two 
very  different  sorts  of  substances  are  usually  included  under 
the  term  colloid,  because  they  show  the  essential  features  of 
colloids  in  most  respects  ;  but  as  in  many  other  respects  they 
are  quite  unlike  each  other,  it  may  be  well  to  distinguish  between 
them  in  some  way.  As  a  type  of  one  class  we  may  take  gela- 
tin ;  of  the  other,  such  a  substance  as  colloidal  arsenic  sulphide. 
Gelatin  solutions  form  gels  upon  cooling  or  evaporation,  and 
redissolve  when  heated  or  when  more  solvent  is  added.  Arse- 
nic sulphide  does  not  form  gels  upon  cooling,  and  when  solidi- 
fied in  any  way,  does  not  redissolve.  In  addition,  the  gelatin 
type  is  very  viscous,  and  is  not  coagulated  by  the  presence  of 
salts  unless  these  are  added  in  large  amounts ;  while  the  other 
type  does  not  render  the  fluid  in  which  it  is  dissolved  appreci- 
ably more  viscid,  and  it  forms  a  precipitate  immediately  if 
minute  amounts  of  electrolytes  are  introduced.  As  the  former 
type  resembles  in  many  details  the  true  solutions,  while  the 
latter  approaches  more  closely  to  the  suspensions,  it  has  been 
proposed  to  distinguish  them  by  the  terms  "  colloidal  solution  " 
and  "  colloidal  suspension.  "  l  Of  the  two  types,  the  colloidal 
solutions  are  by  far  the  more  important  in  biological  considera- 
tions, since  the  colloidal  suspensions  are  usually  prepared  arti- 
ficially and  seldom  occur  in  nature,  e.  g.,  Bredig's  colloidal 
suspensions  of  the  noble  metals. 

The    colloidal    solutions  of  proteids,    which    constitute   the 
chief  part  of  every  cell,  are  of  two  types — one,  such  as  albu- 
min, forms  a  coagulum  when  heated,  which,  under  ordinary  con- 
ditions is  not  reversible ;   that   is,    it  does  not  again  go  into 
1  Noyes,  American  Chemical  Journal,  1905  (27),  85. 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL        51 

solution.  Gelatin,  however,  becomes  more  fluid  when  heated, 
and  when  cooled,  it  forms  a  gel  which  is  readily  reversible  to 
the  soluble  form  under  the  influence  of  heat.  Agar  is  another 
familiar  example  of  this  heat-reversible  type.  Within  the 
cell,  so  far  as  we  know,  occur  only  the  first  type,  the  proteids 
that  form  non-reversible  coagula. 

An  extensive  study  of  the  physical  structure  of  the  colloids 
has  been  made  by  Hardy.1  As  long  as  the  colloid  is  in  solution 
it  is  structureless,  although,  as  before  mentioned,  the  existence 
of  free  solid  particles  can  be  demonstrated  by  certain  optical 
methods.  The  solution  is  homogeneous,  and  although  perhaps 
viscid,  still  it  is  a  typical  solution.  Such  solutions  can  become 
solid,  either  by  the  effect  of  temperature,  of  certain  chemical 
fixing  agents,  or  physical  means.  It  was  found  by  Hardy 
that  in  undergoing  this  solidification  there  occurred  a  separation 
of  the  solid  from  the  liquid,  the  solid  particles  adhering  to 
form  a  framework  holding  the  liquid  within  its  interstices. 
Heat-reversible  gels  show  no  structure  until  they  are  made 
irreversible  by  hardening  agents,  etc. ;  e.  g.y  a  jelly  of  gelatin 
appears  structureless,  but  when  treated  with  formalin  or  other 
fixing  agent,  the  structural  appearances  described  below  appear. 
The  figures  formed  by  the  framework  vary  according  to  the 
nature  and  concentration  of  the  colloid  and  of  the  solvent, 
and  also  upon  the  fixing  agent  used,  the  temperature,  and  the 
presence  or  absence  of  extraneous  substances.  In  general,  how- 
ever, the  figures  obtained  in  the  solidification  of  proteid  solu- 
tions by  fixing  agents,  such  as  bichloride  of  mercury  or  formalin, 
bear'  a  striking  resemblance  to  the  finer  structures  of  protoplasm 
as  described  by  cytologists.  There  is  produced  an  open  net- 
work structure  with  spherical  masses  at  the  nodal  points,  or 
minute  vesicles  hollowed  out  in  a  solid  mass,  or  a  honeycomb 
appearance,  or,  when  the  concentration  of  the  colloid  is  very 
slight,  perhaps  there  is  only  a  precipitation  of  fine  granules  of 
proteid  such  as  we  often  see  in  histological  preparations  of 
edematous  cells  and  tissues.  All  these  forms  seem  to  depend 
chiefly  upon  the  concentration  of  the  colloid.  The  important 
fact  is  that  when  the  chemicals  ordinarily  used  as  fixatives  of 
cells  for  histological  purposes  act  upon  solutions  of  colloids 
that  are  perfectly  homogeneous,  they  produce  very  constant  and 
characteristic  formations  which  recall  at  once  the  structures 
found  in  the  protoplasm  of  hardened  cells.  Moreover,  the  use 
of  different  fixing  agents,  such  as  osmic  acid,  formalin,  and 
bichloride  of  mercury,  produce  just  the  same  differences  in  the 
1  Journal  of  Physiology,  1899  (24),  158. 


52  INTRODUCTION 

structure  of  colloidal  solutions  that  they  produce  in  the  proto- 
plasm of  cells  hardened  by  them.  Neither  are  the  appearances 
seen  in  unfixed  specimens  reliable  indications  of  the  true  struc- 
ture of  the  living  protoplasm.  Granules  of  secretion  may 
disappear  after  or  during  the  death  of  the  cell  (e.  g.,  glyco- 
gen)  or  they  may  swell  up  (e.  g.,  mucin  granules)  thus  giving 
the  appearance  of  a  network  or  honeycomb  which  is  then 
incorrectly  ascribed  to  the  protoplasm  itself.  Death  of  the 
cells,  even  when  not  produced  by  external  influences,  seems 
to  be  accompanied  by  coagulation  of  some  parts  of  the  cell  con- 
stituents, and  hence  a  cell  examined  in  anything  but  its  normal 
living  condition,  an  extremely  difficult  matter,  will  not  present 
a  true  idea  of  how  it  appears  and  is  composed  while  in  that 
condition. 

If,  with  these  facts  in  mind,  we  consider  the  theories  of 
morphologists  as  to  the  finer  structure  of  the  cell  protoplasm 
based  upon  studies  of  cells  fixed  in  various  hardening  agents, 
it  becomes  evident  that  the  possibility  that  the  "  foam  structure" 
advocated  by  Biitschli,  or  the  "  thread/'  "  reticular, "  and 
"  pseudo-alveolar  "  structures  of  Fromann,  Arnold,  Reinke,  and 
others,  are  all  simply  the  effect  of  fixatives  upon  colloid  solutions 
seems  very  real.  The  objection  always  advanced  to  these 
theories  of  protoplasmic  structure,  namely,  that  the  structures 
described  were  artificial  productions,  not  present  in  the  normal 
living  cell,  and  variously  described  and  interpreted  by  different 
investigators  because  each  worked  with  a  different  hardening 
fluid  or  different  technic,  is  strongly  supported  by  these  obser- 
vations upon  colloids.  The  possibility  that  the  living  proto- 
plasm is  homogeneous  still  remains  open.  This  matter  will 
receive  further  consideration  in  the  next  section. 

THE    STRUCTURE    OF   THE   CELL    IN    RELATION   TO   ITS 

CHEMISTRY  AND  PHYSICS 

It  is  obviously  impossible  to  separate  nuclei,  nucleoli, 
cytoplasm,  and  cell  membranes  from  each  other  and  to  isolate 
them  in  quantities  sufficient  for  analysis,  and  therefore  we  are 
still  quite  uncertain  as  to  just  the  chemical  differences  that  exist 
between  them.  That  there  are  differences  is  certain,  and  by 
means  of  micro-chemical  reactions,  by  comparing  analyses  of 
cells  in  which  nucleus  or  cytoplasm  predominate,  and  by  study- 
ing their  physico-chemical  relations  to  one  another,  we  have 
arrived  at  more  or  less  tangible  ideas  on  the  question  of 
the  relation  of  the  structural  elements  of  the  cell  to  its 
composition. 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL        53 
THE    NUCLEUS1 

Although  the  nucleus  presents  morphologically  a  sharp  iso- 
lation from  the  cytoplasm,  and  displays  equally  sharp  tinctorial 
differences,  it  is  probable  that  chemically  the  differences  be- 
tween nucleus  and  cytoplasm  are  quantitative  rather  than  quali- 
tative. The  characteristic  affinity  of  certain  elements  of  the 
nucleus  for  basic  stains  depends  upon  the  presence  in  the 
nucleus  of  nucleoproteids  in  large  proportion,  and  to  a  lim- 
ited degree  nucleoproteids  are  characteristic  of  nuclei.  Their 
affinity  for  basic  dyes  depends  upon  their  acidity,  which  is  due 
to  the  nucleic  acid  radicle.  In  inverse  proportion  to  the  degree 
to  which  this  acidity  is  neutralized  by  proteid  groups  in  the 
nucleo-proteid  molecule,  the  nucleo-proteid  will  show  affinity  for 
basic  dyes.  For  example,  the  heads  of  spermatozoa  contain 
nucleic  acid  bound  to  little  or  no  proteid,  hence  they  are 
very  acid,  have  a  corresponding  affinity  'for  basic  dyes,  and 
appear  intensely  stained  by  hematoxylin,  etc.  Ordinary 
chromatin  threads  of  nuclei  appear  to  contain  somewhat 
more  proteid  in  their  nucleoproteid  molecules,  and  hence 
stain  less  intensely  than  do  the  spermatozoa  heads,  except 
when  in  karyokinesis,  when  the  chromatin  nucleoproteid 
seems  to  approach  that  of  the  spermatozoa  in  acidity.  We 
also  have  nucleoproteids  with  the  nucleic  acid  so  thoroughly 
saturated  by  proteid  that  they  do  not  stain  at  all  by  basic  dyes, 
and  these  seem  to  exist  principally  in  the  cytoplasm,  and  also 
to  form  the  ground-substance  of  the  nuclei,  occupying  the  spaces 
between  the  chromatin  particles  (this  achromatic  substance  of 
the  nuclei  is  called  linin  or  plastin  by  some  cytologists).  Besides 
the  chromatin  and  the  nucleoli,  there  is  a  peculiar  chromatophile 
substance,  suspended  in  the  finer  part  of  the  nuclear  structure 
in  the  same  manner  as  the  chromatin  itself  is  in  the  coarser 
portions  ;  this  was  called  lanthanin  by  Heidenhain, 2  and  is  prob- 
ably similar  to  the  substances  also  described  as  parachromatin 
and  paralinin.  Undoubtedly  the  other  forms  of  proteids  found 
in  the  cell,  such  as  globulin,  albumin,  and  nucleoalbumin,  exist 
both  in  the  nucleoplasm  and  in  the  cytoplasm,  the  essential  dif- 
ference being  that  the  proportion  of  nucleoproteid  is  much 
greater  in  the  nucleus,  and  that  the  nucleoproteids  of  the  cyto- 
plasm contain  relatively  more  proteid  in  proportion  to  the 
nucleic  acid  than  do  the  nucleoproteids  of  the  nucleus.  As 
nucleoproteids  are  little  affected  by  peptic  digestion,  it  is  possible 

1  Earlier  literature  by  Albrecht,  "  Pathologic  der  Zelle, "  Lubarsch-Oster- 
tag  Ergeb.  der  allg.  Pathol.,  1899  (6),  900. 

2  Festschr.  f.  Kolliker,  1892,  p.  128. 


54  INTRODUCTION 

to  isolate  nuclear  elements,  especially  the  chromatin,  for  analy- 
tic purposes,  and  it  has  been  demonstrated  by  this  means  also 
that  nuclein  is  the  chief  constituent  of  the  staining  elements. 
The  distribution  in  the  nucleus,  of  the  other  primary  constituents 
of  the  cytoplasm,  such  as  lecithin,  cholesterin,  and  inorganic 
salts  has  not  yet  been  worked  out,  except  that  Macallum l 
has  found  that  nuclei  contain  no  chloride,  as  indicated  by  their 
not  staining  with  silver  nitrate,  and  also  no  potassium.2 

Nucleoli,  which  not  all  varieties  of  nuclei  possess,  differ  from 
the  other  nuclear  structures  in  having  an  affinity  for  acid  rather 
than  for  basic  dyes. 3  Their  chemical  composition  has  not  been 
ascertained.  Zacharias  considers  the  nucleoli  as  composed  of 
nuclein  well  saturated  with  proteid,  because  of  its  staining  reac- 
tions and  its  relative  insolubility  in  alkalies,  and  classes  it  with 
plastin  or  linin,  which  forms  the  achromatic  part  of  the  nucleus 
and  is  also  present  in  the  cytoplasm.  Macallum4  found  that 
they  reacted  for  organic  phosphorus  microchemically,  but  less 
strongly  than  did  chromatin  fibers. 

The  nuclear  membrane  is  an  uncertain  structure,  at  times 
dense  and  staining  as  if  formed  of  a  layer  of  chromatin,  in  other 
cells  staining  like  the  cytoplasm  with  which  it  seems  to  be  con- 
tinuous, in  most  cells  disappearing  during  karyokinesis,  and  in 
some  protozoa  being  entirely  absent.  Naturally  the  composition 
of  the  nuclear  membrane  is  unknown,  but  it  is  probable  that  it 
acts  as  a  diffusion  membrane  of  partially  semipermeable  charac- 
ter, maintaining  different  conditions  in  nucleus  and  cytoplasm. 

Functionally  the  nucleus  is  the  essential  element  of  the  cell ; 
an  isolated  nucleus  may  be  able  to  develop  new  cytoplasm,  but 
isolated  cytoplasm  soon  disintegrates,  although  it  may  manifest 
life  for  some  time  by  movement  and  chemical  activities.  A 
popular  theory  is  that  synthetic,  constructive  processes  occur  in 
the  nucleus  or  under  the  influence  of  its  products,  but  to  what 
the  nucleus  owes  these  hypothetical  powers  is  unexplained. 
More  tangible  are  the  theories  based  upon  the  work  of  Spitzer, 
Loeb, 5  Lillie 6  and  others  which  show  that  the  oxidative  pro- 
cesses of  the  cell  depend  upon  the  nucleus,  hence  portions  of 
the  cell  cut  away  from  the  nucleus  undergo  asphyxiation.  As 

1  Proceedings  of  the  Koyal  Society,  1905  (76),  217. 

2  Jour,  of  Physiol.,  1905  (32),  95.  The  reliability  of  the  method  used  by 
Macallum  has  been  questioned  by  Tracy  (Jour.  Med.  Besearch,  1906  (14),  447). 

3  Nucleoli  of  nerve-cells  are  an  exception,  being  basophilic. 
*Proc.  of  the  Eoyal  Society,  1898  (63),  467. 

5  "  Studies  in  General  Physiology,"  Chicago,  1905. 

6  American  Journal  of  Physiology,  1902  (7),  412. 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL         55 

Loeb  says,  "  By  cellular  structure  we  understand  the  fact  that 
there  must  be  a  definite  maximal  distance  between  the  elements 
of  the  protoplasm  and  the  nearest  nucleus." 

It  should  be  mentioned  that  certain  cells,  such  as  bacteria 
and  algae,  seem  to  have  no  true  nuclei,  but  Macallum l  found 
that  the  forms  he  examined  gave  reactions  for  phosphorus  and 
iron  in  a  similar  way  to  the  nucleoproteids  of  a  nucleus,  suggest- 
ing that  in  such  cells  the  nuclear  elements  are  diffused  through 
the  cell  rather  than  differentiated.  To  quote  Wilson  :  "  The 
terms  f  nucleus '  and  (  cell  body '  should  probably  be  regarded 
as  only  topographical  expressions,  denoting  two  differentiated 
areas  in  a  common  structural  basis." 

Because  of  the  relative  acidity  of  the  nuclei  they  are  electric- 
ally negative  to  the  cytoplasm,  particularly  when  in  karyokine- 
sis.  Sperm-heads  in  isotonic  cane-sugar  solution  move  rapidly 
— 2000  microns  a  minute — toward  the  anode,  when  a  current 
is  passed  through  the  solution  ;  and  leucocytes  also  go  toward  the 
anode  under  the  same  conditions,  the  rate  depending  upon  the 
proportion  of  nucleoplasm  and  cytoplasm,  large  leucocytes  some- 
times even  going  slowly  toward  the  cathode.  The  Sertoli  cells 
of  the  testicle,  which  have  a  round  mass  of  cytoplasm  with  a 
number  of  miniature  spermatozoa  heads  at  one  side,  orient 
themselves  in  the  current  so  that  the  side  or  end  containing  the 
spermatozoa  drags  the  mass  of  cytoplasm  toward  the  positive 
pole. 

THE  CYTOPLASM 

The  cytoplasm,  as  before  mentioned,  contains  all  of  the 
primary  cellular  constituents,  and  also  such  secondary  constit- 
uents as  the  particular  cell  possesses.  Nucleoproteids  are  un- 
doubtedly present  in  unknown  proportions,  but  with  the 
nucleic  acid  well  saturated  by  proteids,  and  perhaps  also  to 
a  large  extent  combined  with  carbohydrates  to  form  the 
glyconucleoproteids.  Sometimes  the  nucleoproteids  of  the 
cytoplasm  may  be  partly  of  the  unsaturated  class,  and  show 
an  affinity  for  basic  stains,  as  in  the  case  of  the  Nissl  bodies 
of  the  nerve-cells,  and  perhaps  also  the  cytoplasm  of  plasma 
cells.  The  great  question  concerning  the  cytoplasm  is  its  struc- 
ture— whether  homogeneous,  alveolar,  areolar,  fibrillar,  foam- 
like,  or  granular.  On  a  previous  page  have  been  mentioned  the 
experiments  of  Hardy,  which  show  that  homogeneous  solutions 
of  proteid,  when  fixed  by  the  same  reagents  as  are  used  in  the 
customary  fixation  of  histological  materials,  may  show  quite  the 
1W  Studies  from  the  University  of  Toronto, "  1900. 


56  INTRODUCTION 

same  microscopical  structures  as  are  shown  by  the  cytoplasm 
of  cells.  Network,  foam,  and  alveolar  structures  are  produced 
in  albumin  and  gelatin  solutions  when  they  are  hardened  by 
bichloride  of  mercury,  osmic  acid,  formalin,  etc.,  and  the  same 
characteristic  differences  that  are  produced  in  cells  by  these  dif- 
ferent reagents  are  likewise  produced  in  the  hardened  proteid 
solution,  Proteid  structures  hardened  under  strain  form  radi- 
ating structures  resembling  centrosomes  and  the  radiating  threads 
seen  in  cells.  If  elder  pith  is  saturated  with  proteid  solutions 
and  then  hardened,  sectioned,  and  stained  by  the  usual  methods, 
appearances  resembling  closely  the  structure  of  a  hardened  cell 
may  be  found  in  the  spaces  of  the  pith — even  a  central,  nucleus- 
like  mass  may  be  suspended  in  a  network  of  anastomosing 
threads.  These  and  many  other  experiments  indicate  that  much 
of  the  work  done  on  cell  structure  by  means  of  studies  of  hard- 
ened cells  cannot  be  considered  of  value  in  deciding  the  struc- 
ture of  living  cells ;  but,  nevertheless,  the  fact  remains  that 
many  cells  that  can  be  observed  while  alive  and  uninjured  under 
the  microscope  are  seen  to  have  a  definite  structure  in  the  cyto- 
plasm, e.  g.,  sea-urchin  eggs,  which  show  a  characteristic  alve- 
olar structure. 

A  compromise  view  of  the  structure  of  protoplasm  (and 
cytoplasm  in  particular)  which  takes  account  of  what  appear  to 
be  facts  brought  out  on  both  sides  of  the  question,  is  that  while 
in  some  cells  definite  structural  arrangements  of  the  cytoplasm 
exist,  in  most  cells,  and  to  a  large  extent  even  in  cells  showing 
a  cytoplasmic  structure,  the  proteids  are  in  a  homogeneous 
solution  ;  most  of  the  structures  seen  in  fixed  cells,  except  the 
chromatin  threads,  nuclear  membrane,  nucleoli,  and  centrosomes, 
are  produced  by  the  coagulation  of  the  proteids,  and  are  not 
present  during  life.  When  a  framework  does  exist,  it  is  a  fair 
inference,  by  analogy  with  the  cell  membrane  and  the  stroma 
of  the  red  corpuscles,  that  the  cell  lipoids  are  largely  responsible 
for  its  formation,  and  that  they  form  a  prominent  part  of  its 
composition.  This  question  of  the  presence  or  absence  of  struc- 
ture in  the  cytoplasm  is  of  more  interest  than  as  a  mere  mor- 
phological problem,  for  if  the  cytoplasm  is  subdivided  into 
innumerable  little  chambers,  each  surrounded  by  a  membrane, 
it  is  probable  that  processes  of  diffusion  and  conditions  of 
osmotic  pressure  will  be  very  different  from  what  they  would  be 
if  the  cytoplasm  were  a  simple  homogeneous  colloid  solution,  like 
a  lump  of  semisolid  gelatin  or  agar.  In  such  colloidal  masses 
diffusion  and  osmosis  go  on  almost  as  if  there  were  no  colloids 
in  the  solvent  at  all,  whereas  most  membrane  structures  that 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL         57 

are  found  in  living  tissues  seem  to  have  a  decidedly  semiperme- 
able  character. 

From  what  we  know  at  the  present  time  of  intracellular 
physics  and  chemistry  there  is  no  necessity  for  assuming  that 
sernipermeable  septa  exist  within  the  cell.  All  the  intracellular 
processes  with  which  we  are  familiar  could  go  on  without  such 
structures.  It  is  not  necessary  to  assume  a  compartment 
structure  to  explain  the  possibility  of  different  chemical 
reactions  going  on  in  different  parts  of  the  cell  at  the  same 
time,  for  most  of  the  cell  reactions  seem  to  depend  on  enzymes, 
which  we  know  are  not  readily  diffusible  in  solutions  of  colloids, 
and,  therefore,  might  remain  fixed  without  requiring  any 
enclosing  walls  or  retaining  framework.  Certainly,  many  cells 
are  free  from  structural  cytoplasm,  for  we  see  particles  of  solid 
matter  moving  about  within  them  quite  freely.  In  some  cells 
the  nuclei  migrate  about  in  the  cell,  as  also  do  digestive  and 
excretory  vacuoles,  which  motion  would  seem  to  be  rather 
destructive  if  the  protoplasm  had  a  structure  at  all  permanent. 

When  a  portion  of  the  cytoplasm  is  cut  free  from  the  body  of 
certain  cells  it  at  once  forms  a  round  drop,  just  as  any  insolu- 
ble fluid  would  do  in  another  of  different  surface  tension,  and 
not  at  all  as  if  it  were  bound  into  a  fixed  structure  by  a  frame- 
work. Other  cells,  however,  retain  their  form  under  the  same 
conditions.  The  structure  of  even  so  evidently  complicated  a 
cytoplasm  as  that  of  striated  muscle-fibers  is  in  doubt ;  a  clas- 
sical observation  on  this  point  is  the  passage  of  a  minute  worm 
through  the  substance  of  a  muscle-cell,  its  progress  being  as 
unimpeded  as  if  there  were  no  such  things  as  disks,  bands,  rods, 
and  striae  in  the  cell.  Many  features  of  ameboid  movement  also 
seem  to  indicate  that  the  cytoplasm  follows  much  the  same  laws 
as  a  drop  of  fluid  in  a  heterogeneous  medium,  for  we  can  make  a 
drop  of  mercury  or  of  chloroform  in  water,  or  of  oil  in  weak 
alcohol,  react  to  various  stimuli  in  much  the  same  way  that  an 
ameba  would. 

The  question  of  structure  in  the  nucleus  is  quite  a  different 
matter,  in  so  far  as  the  chromatin  threads  and  the  nucleolus  are 
concerned.  In  ameboid  movement  the  nucleus  seems  to  play 
a  passive  role  and  to  be  dragged  about  by  the  cytoplasm,  indicating 
quite  a  high  degree  of  rigidity.  It  is  probable,  however,  that  the 
achromatic  portion  between  the  chromatin  threads  and  granules 
has  much  the  same  structure  or  lack  of  structure  as  the  cytoplasm. 

The  inorganic  salts  seem  to  be,  at  least  in  part,  contained  in 
the  cells  in  chemical  combination  rather  than  in  simple  solution 
in  the  water  of  the  cell.  There  is  much  evidence  indicating 


58  INTRODUCTION 

that  they  form  with  the  proteids  ion  compounds,  which  may  be 
altered  under  various  conditions.  For  example,  Loeb  found 
that  muscles  placed  in  solutions  of  potassium  salts  took  up 
much  water,  whereas  if  placed  in  a  solution  of  calcium  salts 
they  lost  water,  exactly  as  soaps  do  when  potassium  or  calcium 
ions  are  substituted  for  the  sodium  ions  in  a  sodium  soap.  He 
has  suggested  that  we  have  in  the  cells  a  proteid-ion  compound, 
after  this  order, 

/Na 
Proteid— K 

\Ca 

and  that  if,  in  the  surrounding  fluid,  a  great  excess  of  one  of 
these  ions  is  present,  it  may  displace  the  others  by  mass  action, 
forming  a  proteid  with  all  or  most  of  the  ions  of  one  kind,  and, 
therefore,  decidedly  abnormal.  Many  features  of  cell  physiol- 
ogy seem  explainable  on  these  grounds,  and  the  reader  is  referred 
to  Loeb's  collected  works  for  further  discussion.1  In  any 
event  it  is  important  for  the  cell  that  the  proportion  of  the 
inorganic  constituents  be  maintained  in  rather  constant  con- 
ditions of  quality  and  quantity.2 

The  various  secretory  granules,  fat-droplets,  pigment-granules, 
glycogen  granules,  keratin,  etc.,  that  may  lie  in  the  cytoplasm, 
are  inconstant  constituents,  varying  with  different  cells,  and 
under  varying  conditions  in  the  same  cells,  and  lie  beyond  the 
scope  of  our  discussion  of  the  general  composition  of  the  cell. 

THE  CELL-WALL 

The  cell  membrane  in  most  animal  cells  is  inconspicuous 
structurally,  but  in  discussing  osmosis  it  was  shown  that  it  is  of 
the  greatest  biological  importance.  There  is  no  direct  chemical 
or  microscopical  evidence  at  hand  showing  the  composition  of  the 
animal  cell  membrane,  but  by  observations  on  its  behavior 
when  the  cells  are  in  solutions  of  different  sorts,  facts  have  been 
collected  indicating  that  lecithin  and  cholesterin,  and  probably 
the  allied  fat-like  bodies,  "  protagon  "  and  cerebrin,  are  promi- 
nent constituents.  The  substances  that  diffuse  through  most 
cell  walls  are  just  the  substances  that  are  soluble  in  or  dissolve 
these  lipoids,  e.  g.,  alcohol,  chloroform,  ether,  etc.,  and  it  is 

1  "  Studies  in  General  Physiology,"  1905. 

2  According  to  Macallum,  potassium  can  be  demonstrated  by  microchemical 
methods  in  the  cytoplasm  and  extracellular  structures,  but  this  could  not  be 
confirmed  by  Tracy  (  Jour.  Med.   Research,  1906  (14),  447),  who  questions 
the  reliability  of  the  method,  and  states  that,  if  the  reaction  indicates  anything, 
the  potassium  is  chiefly  in  the  nucleus. 


THE  CHEMISTRY  AND  PHYSICS  OF  THE  CELL         59 

probable  that  the  anesthetic  effects  of  many  of  these  substances 
depend  in  some  way  on  their  fat-dissolving  power  and  the 
large  proportion  of  lipoids  in  nerve-cells.  These  observations 
were  made  first  by  Overton l  and  Meyer.2  Of  particular 
interest  for  our  purpose  are  Overton' s  observations  on  the  effects 
of  dyes  on  living  cells.  The  best  known  vital  stains  (i.  e.y  stains 
that  will  enter  the  living  cell  without  requiring  or  causing 
injury  to  it)  are  neutral  red,  methylene  blue,  toluidiu  blue, 
thionin,  and  safranin.  If  uninjured  cells,  e.  g.,  frog  eggs,  are 
placed  in  watery  solutions  of  these  dyes  they  soon  become  filled 
with  the  coloring-matter,  which  seems  to  penetrate  the  cell  mem- 
brane quite  uniformly  at  all  points ;  if  the  dyed  eggs  are  then 
placed  in  clear  water,  the  stain  diffuses  out  again,  showing  it  to 
be  simply  absorbed,  rather  than  chemically  combined.  In  con- 
trast to  these  stains  the  sulphonic  acid  dyes,  such  as  indigo  car- 
mine and  water-soluble  indulin,  nigrosin,  and  anilin  blue,  do 
not  penetrate  the  living  cell  at  all.  Overton  tested  the  solubil- 
ity of  these  last-named  dyes  and  found  them  all  insoluble  in 
oils,  fats,  and  fatty  acids  ;  but  the  first  group,  those  staining 
living  cells,  were  readily  soluble  in  lecithin,  cholesterin, 
*'  protagon,"  and  cerebrin,  the  so-called  cell  lipoids.  Fur- 
thermore, if  crumbs  of  lecithin,  "  protagon,"  or  cerebrin  were 
placed  in  very  dilute  watery  solutions  of  these  dyes,  they  were 
found  to  absorb  from  the  water  the  vital  stains,  but  not  the 
others,  which  indicates  that  stains  that  penetrate  living  cells 
are  more  soluble  in  lecithin  than  they  are  in  water. 

Many  facts  indicate  that  the  delicate  membrane  of  animal 
cells  has  the  features  of  a  semipermeable  membrane,  to  the 
extent  of  permitting  certain  substances  to  diffuse  through  and 
not  others.  Had  it  the  property  of  many  of  the  artificial  semi- 
permeable  membranes,  of  letting  water  pass  through  but  holding 
back  almost  absolutely  all  crystalloids,  the  result  would  be  the 
development  of  an  enormous  disproportion  in  the  pressure 
between  the  inside  and  the  outside  of  the  cell.  Furthermore, 
the  exchange  of  nutritive  material  and  excretion  products 
between  the  blood  and  the  cells  would  be  impossible.  But  per- 
mitting some  substances  to  pass  through  the  cell  membrane 
results  in  their  accumulation  within  the  cell,  until  they  are  in 
sufficient  concentration  to  neutralize  the  osmotic  pressure 
exerted  on  the  outside  of  the  cell.  As  evidence  of  this  elective 
permeability  we  have  the  fact  that  the  proportion  of  certain 
salts  within  the  cell  is  quite  different  from  what  it  is  in  the 

1  Jahrb.  f.  wissentschaftl.  Botanik,  1900  (34),  669. 

2  Arch.  f.  exp.  Path.  u.  Pharm.,  1899  (42),  109. 


60  INTRODUCTION 

fluids  bathing  them;  e.  g.,  animal  cells  generally  contain  more 
potassium  and  less  sodium  than  the  fluids  surrounding  them. 
The  inorganic  constituents  of  red  cells  are  totally  different  from 
those  of  the  plasmar  the  corpuscles  not  containing  any  calcium  at 
all,  while  the  magnesium  seems  to  enter  them  freely ;  in  other 
words,  the  red  corpuscle  seems  to  be  impermeable  to  calcium 
and  permeable  to  magnesium.  If  the  salts  in  a  corpuscle  are  in 
smaller  proportion  than  in  the  surrounding  fluid,  it  indicates  that 
the  cell  membrane  is  not  freely  permeable  for  them ;  if  in 
greater  proportion,  that  some  constituent  of  the  cell  is  holding 
them  in  combination,  possibly  as  ion-proteid  compounds.  Prob- 
ably inorganic  salts  are  present  in  the  cell  by  virtue  of  both 
physical  and  chemical  influences,  some  simply  diffusing  in  and 
out,  others  combining  with  the  proteids  and  being  held  chemi- 
cally. 

The  intercellular  substance  varies  greatly  in  different 
tissues.  In  the  case  of  the  supportive  tissues  it  is  the  impor- 
tant element,  and  the  cells  seem  to  exist  chiefly  for  the  purpose 
of  forming  and  keeping  it  in  repair  as  it  is  worn  out.  In  the 
epithelial  and  secreting  tissues,  however,  the  intercellular  sub- 
stance is  reduced  to  a  minimum,  except  in  so  far  as  a  cement 
substance  is  required,  and  the  cells  generally  lie  in  almost 
immediate  apposition.  It  is  probable  that  there  is  a  greater  or 
less  amount  of  cement  substance,  even  between  the  most  closely 
applied  cells,  and  this  substance  seems  to  be  related  to  mucin. 
It  can  generally  be  brought  out  by  staining  with  silver  nitrate, 
and  Macallum  l  points  out  that  this  reaction  is  merely  a  micro- 
chemical  test  for  chlorides,  and  indicates  that  the  cement  sub- 
stance contains  them  in  larger  proportion  than  does  the  cyto- 
plasm. 

1  Proceedings  of  the  Koyal  Society,  1905  (76),  217. 


CHAPTER    II 
ENZYMES 

EVERY  cell  is  constantly  accomplishing  an  enormous  number 
of  chemical  reactions  of  varied  natures,  at  one  and  the  same  time  ; 
how  many  we  do  not  know,  but  the  score  or  more  that  we  do 
know  to  be  constantly  going  on  in  the  liver  cell,  for  example,  are 
probably  but  a  part  of  the  whole.  Furthermore,  reactions  take 
place  between  substances  that  show  no  inclination  to  affect  each 
other  outside  the  body,  and  proceed  in  directions  that  we  find  it 
difficult  to  make  them  take  in  the  laboratory.  Sugar  is  being 
constantly  oxidized  into  carbon  dioxide  and  water,  a  decomposi- 
tion that  requires  high  degrees  of  heat  or  powerful  chemicals  to 
bring  about  in  the  reagent  glass.  Proteids  are  being  continu- 
ally broken  down  into  urea,  carbon  dioxide,  and  water ;  yet  to 
split  proteids  even  as  far  as  the  amino-acid  stage  requires  pro- 
longed action  of  concentrated  acids  or  alkalies,  or  superheated 
steam  under  great  pressure.1  But  all  the  time  in  the  cell  a 
multitude  of  equally  difficult  changes  is  going  on  at  once, 
within  its  tiny  mass,  always  keeping  the  resulting  heat  within 
a  fraction  of  a  degree  of  constant,  and  the  resulting  products 
within  narrow  limits  of  concentration.  We  have  already  indi- 
cated the  means  used  to  keep  the  concentration  of  the  cell  prod- 
ucts within  safe  limits ;  namely,  the  processes  of  diffusion  and 
osmosis  and  their  modification  by  the  cell  structure.  The 
forces  that  bring  about  the  chemical  reactions  reside,  we  say,  in 
enzymes,  although  in  so  doing  we  only  shift  the  attribute 
formerly  conceded  to  the  cell,  to  certain  constituents  of  the  cell 
whose  nature  and  manner  of  action  are  equally  unknown. 
When  the  only  enzymes  that  were  known  were  limited  to  those 
secreted  from  the  cell,  and  found  free  in  fluids,  such  as  pepsin 
and  trypsin,  the  chemical  changes  that  went  on  in  the  cell  were 
ascribed  to  its  "vital  activity."  Buchner,  by  devising  a 
method  to  crush  yeast  cells,  and  finding  the  expressed  cell  con- 
tents able  to  produce  the  same  changes  in  carbohydrates  that 
the  cells  themselves  did,  proved  the  existence  within  living 
cells  of  enzymes  similar  to  those  excreted  by  certain  cells,  and 

1  For  a,  fuller  consideration  of  these  phases  of  cell  activity  read  Hofmeister, 
"  Die  chemische  Organisation  der  Zelle,"  Braunschweig,  1901. 

61 


62  ENZYMES 

substantiated  the  belief  of  their  existence  that  had  become 
general  before  it  was  thus  finally  corroborated.  Growing  out 
from  this  and  subsequent  experiments  has  come  a  larger  and 
larger  amount  of  evidence  that  many  of  the  chemical  activities 
of  the  cells  are  due  to  the  enzymes  they  contain,  until  now  the 
point  is  reached  where  one  may  rightfully  ask  if  cell  life  is  not 
entirely  a  matter  of  enzyme  activity.  There  are  certain  facts, 
however,  which  seem  to  indicate  that  there  are  some  essential 
differences  between  cells  and  enzymes.  One  of  the  most 
important  of  these  is  the  difference  in  the  susceptibility  to  poi- 
sons of  enzymes  and  cells.  Strengths  of  antiseptics  that  will 
either  destroy  or  inhibit  the  action  of  living  cells,  such  as  alco- 
hol, ether,  salicylic  acid,  thymol,  chloroform,  tuluol,  and  sodium 
flouride,  will  harm  free  enzymes  in  solution  little  or  not  at  all. 
This  fact  has  been  of  great  assistance  in  distinguishing  between 
the  action  of  enzymes  and  of  possible  contaminating  bacteria  in 
experimental  work.  Although  this  difference  between  enzymes 
and  cells  is  characteristic,  it  does  not  finally  decide  that  the  cell 
actions  are  not  enzyme  actions,  for  it  may  well  be  that  the  poi- 
sons act  chiefly  by  altering  the  physical  conditions  of  the  cell 
so  that  diffusion  is  interfered  with,  thus  seriously  interfering 
with  the  exchange  of  splitting  products  between  different  parts 
of  the  cell,  and  checking  intracellular  enzyme  action,  which  we 
shall  see  later  requires  free  diffusion  of  the  products  for  its  con- 
tinuance.1 At  the  very  least,  however,  we  may  look  upon  the 
intracellular  enzymes  as  the  most  important  known  agents  of 
cell  metabolism,  and  consequently  of  all  life  manifestations,^ 
and  the  changes  they  undergo  or  produce  in  pathological  condi- 
tions must  be  fully  as  fundamentally  important  as  is  their  rela- 
tion to  physiological  processes.  It  therefore  becomes  necessary 
for  us  to  consider  carefully — 

THE  NATURE  OF  ENZYMES  AND  THEIR  ACTIONS  2 

Since  up  to  the  present  time  no  ferment  has  been  isolated  in 
an   absolutely   pure  condition   we  are  entirely  unfamiliar  with 

1  Kaufman  points  out  another  important  defect  in  the  experiments  indicating 
a  difference  between  the  effects  of  poisons  on  enzymes  and  on  cells,  namely,  that 
in  the  experiments  the  concentration  of  enzymes  is  high,  whereas  in  most  cells- 
it  is  low.     Solutions  of  trypsin   stronger  than   0.2  per  cent,  are  not  much 
affected  by  toluol,  thymol,  etc.,  during  twenty-four  hours,  but  weaker  solu- 
tions are — those  less  than  0.02  per  cent,  being  rendered  inert.       (Zeitschr. 
f.  physiol.  Chem.,  1903  (39),  434.) 

2  It  would  not  be  profitable  to  discuss  fully  all  the  various  theories  and  hypoth- 
eses that  have  been  advanced,  but  the  reader  is  referred  to   the   following 
chief  compilations  of  the  entire  subject :  Oppenheimer,  "  Die  Fermente  und 
ihre  Wirkungen,"  Leipzig,  1903,  Effront,  "  Enzymes  and  their  Applications," 


THE  NATURE  OF  ENZYMES  AND   THEIR  ACTIONS     63 

their  chemical  characters,  and  consequently  are  obliged  to 
recognize  them  solely  by  their  action.  As  far  as  we  know,  true 
enzymes  never  occur  except  as  the  result  of  cell  life — they  are 
produced  within  the  cell,  and  increased  in  amount  by  each  new 
cell  that  is  formed,  and,  furthermore,  they  are  present  in  every 
living  cell  without  exception.  As  the  same  facts  are  equally 
true  of  the  proteids,  and  apparently  true  of  nothing  else,  it  is 
natural  to  associate  the  enzymes  with  proteids,  and  so  explain 
the  importance  of  the  proteids  for  cell  life.1  If  enzymes  are 
obtained  in  any  of  the  usual  ways  from  animal  cells  or  secre- 
tions they  are  always  found  to  give  the  reactions  for  proteids, 
even  if  repurified  many  times.  But  it  is  well  known  that 
whenever  proteids  are  precipitated  the  other  substances  in  the 
solution  tend  to  be  dragged  down  by  the  colloids,  and  it  is 
possible  that  the  enzymes  are  merely  associated  with  the  pro- 
teids in  this  way.  Furthermore,  enzymes  are  known  to  become 
so  closely  attached  to  stringy  proteid  masses,  such  as  fibrin  and 
silk,  that  they  cannot  be  removed  by  washing.  Some  have 
claimed  that  they  have  secured  active  preparations  of  pepsin 
and  invertase  that  did  not  give  proteid  reactions  and  contained 
very  little  or  no  ash  or  carbohydrate  ;  but  it  has  so  far  been 
impossible  to  secure  trypsin  free  from  proteid,  and  diastase 
seems  to  be  certainly  of  proteid  nature.  Analyses  of  enzymes 
purified  as  completely  as  possible  do  not  have  great  worth,  for 
the  "  purified  "  enzymes  are  probably  far  from  pure ;  however, 
it  is  of  some  importance  that  they  vary  greatly  in  the  propor- 
tions of  carbon,  hydrogen,  and  nitrogen  which  they  contain, 
indicating  that  possibly  different  enzymes  may  be  of  very 
different  nature.  Active  gum  enzymes,  with  oxidizing  proper- 
ties, are  said  to  have  been  prepared  free  from  nitrogen.2  Macal- 
lum  has  shown  microchemically  that  phosphorus  is  closely 
associated  with  the  formation  of  zymogen  granules  in  cells, 
which  seem  to  be  started  in  the  nucleus ;  and  there  are  many 
other  observations  suggesting  that  certain  ferments  are  closely 
related  to  the  nucleo-proteids.  This  is  particularly  true  of  the 
oxidases,  which  seem  also  to  contain  iron  and  manganese.  A 
final  point  of  importance  in  support  of  the  proteid  nature  of 

translated  by  S.  C.  Prescott,  New  York,  1902.  Keynolds  Green,  "  Soluble 
Ferments  and  Fermentation,"  1901.  In  this  chapter  references  will  not 
usually  be  cited  unless  they  are  from  works  published  later  than  Oppenheimer's 
book,  in  which  all  original  work  of  importance  can  be  found. 

1  Another  important  point  is  that  the  closest  imitation  of  enzymes,  Bredig's 
"  inorganic  ferments, "  seem  to  owe  their  action  to  their  colloidal  nature. 

2  A  recent  paper  by  Tschirsch  and  Stevens  casts  considerable  doubt  upon 
this  statement  (Pharmac.  Centrhalle.,  1905  (56),  501.) 


64  ENZYMES 

enzymes  is  that  pepsin   destroys   trypsin   and  diastase,  while 
trypsin  destroys  pepsin. 

So  uncertain,  however,  is  our  information  concerning  the 
chemical  nature  of  the  enzymes,  that  it  has  become  possible  for 
a  hypothesis  to  be  developed  urging  that  enzymes  are  immate- 
rial, that  the  actions  we  consider  as  characterizing  enzymes  are 
the  result  of  physical  forces  which  may  reside  in  many  sub- 
stances, and  perhaps  even  free  from  visible  matter.  Arthus, 
who  has  been  the  chief  champion  of  this  very  interesting  con- 
ception, compares  enzyme  action  to  such  forces  as  magnetism. 
A  magnetic  iron  bar  loses  its  characteristic  property  when 
sufficiently  heated,  just  as  an  enzyme  does.  Dissolve  the  mag- 
net or  the  enzyme  in  strong  hydrochloric  acid  and  they  both 
lose  their  power  to  affect  other  substances.  It  has  been  equally 
impossible  to  isolate  enzymes  and  magnetism,  both  of  which 
are  recognized  by  their  actions,  and  not  by  themselves.  Just 
as  light,  heat,  and  electricity  were  once  considered  as  matter,  so 
has  it  also  been  with  enzymes,  and  Arthus  believes  that  they 
will  eventually  be  stricken  from  the  list  of  material  things  and 
considered  as  forms  or  a  form  of  energy.  There  can  be  no 
question  that  this  conception  rests  on  strong  grounds,  and  it 
possesses  the  stimulating  qualities  that  make  a  hypothesis  help- 
ful, but,  as  Oppenheimer  says,  all  chemical  substances  may  be 
considered  in  the  same  way.  We  recognize  all  bodies  through 
some  form  of  energy  ;  if  we  speak  of  sulphuric  acid,  it  is  really 
of  the  properties  of  energy  it  shows,  such  as  its  taste,  which  is 
the  energy  imparted  by  its  ions  to  the  nervous  system  ;  or  its 
combining  with  bases,  etc.,  which  .also  is  a  manifestation  of 
energy.  In  the  same  way  we  recognize  the  ferments,  and  we 
may  properly  believe  them  to  be  fully  as  much  definite  sub- 
stances as  is  sulphuric  acid.  The  magnet  comparison  also 
falls  when  we  remember  that  the  magnetism  can  be  introduced 
into  a  bar  of  iron  and  removed  at  will,  but  as  yet  it  has  not 
been  possible  to  introduce  enzymatic  properties  into  an  inert 
proteid,  or  to  restore  them  to  an  enzyme  that  has  been 
destroyed  by  heat. 

Another  valuable  piece  of  evidence  of  the  material  existence 
of  enzymes  is  their  specific  nature,  lipase  affecting  only  fats, 
and  trypsin  only  proteids,  indicating  chemical  individuality. 
They  are  true  secretions,  formed  within  the  cell  by  recognizable 
steps ;  and,  furthermore,  when  injected  into  the  body  of  an  ani- 
mal, they  give  rise  to  the  formation  of  specific  immune  bodies 
that  antagonize  their  action.  Emil  Fischer's  work  with  the 
sugar-splitting  enzymes,  moreover,  indicates  that  they  owe  their 


THE  PRINCIPLES  OF  ENZYME  ACTION  65 

action  to  their  stereochemical  configuration.  He  prepared  two 
sets  of  sugar  derivatives  which  differed  from  each  other  solely 
in  the  arrangement  of  their  atoms  in  space  (i.  e.,  isomers)  and 
found  that  one  specific  enzyme  would  split  members  of  only 
one  of  the  varieties,  while  another  enzyme  would  act  only  on 
the  variety  with  the  opposite  isomeric  form.  These  experi- 
ments make  it  very  probable  that  there  must  be  a  certain 
relation  of  geometrical  structure  between  an  enzyme  and  the 
substances  it  acts  upon,  and  leaves  little  question  of  its 
material  nature. 

Bredig  1  has  found  that  colloidal  solutions  of  metals  have 
many  of  the  properties  of  true  enzymes,  accomplishing  many 
of  the  decompositions  produced  by  enzymes,  being  affected  by 
temperatures  of  nearly  the  same  degree,  and  even  being  "poi- 
soned "  by  substances  that  destroy  or  check  enzymes.  The 
only  possible  explanation  of  these  observations  seems  to  be  that 
the  enzyme  effects  are  brought  about  by  surface  phenomena.  A 
colloidal  solution  of  platinum,  so  far  as  is  known,  differs  from 
a  piece  of  metallic  platinum  solely  in  the  enormously  great 
amount  of  surface  it  offers  in  proportion  to  its  weight,  and  it  is 
well  known  that  surfaces  may  affect  chemical  action.  Hence 
we  have  the  possibility  that  some  enzyme  actions,  at  least,  may 
depend  upon  the  existence  of  a  very  large  surface,  and  since  by 
no  means  all  colloids  are  enzymes,  that  this  surface  must  bear 
a  certain  relation  in  form  to  the  surface  of  the  body  that  is  to 
be  acted  upon. 

THE  PRINCIPLES  OF  ENZYME  ACTION 

The  effects  produced  by  enzymes,  which  at  one  time  were 
considered  quite  unique  and  remarkable,  have  now  been  made 
comparatively  plain,  chiefly  through  the  observations  of  Ost- 
wald  on  related  chemical  reactions  ;  and  by  the  investigations 
of  Croft  Hill,  Kastle  and  Loevenhart,  and  others,  on  enzymes, 
which  show  that  enzyme  action  is  in  no  way  different  from 
chemical  action  observed  independent  of  enzymes.  The  funda- 
mental consideration  is  that  chemical  reactions  are  reversible, 
that  is,  that  their  tendency  is  to  establish  an  equilibrium,  and 
that  the  change  may  be  from  either  side  of  the  equation.  The 
action  of  enzymes  is  similar  to  that  of  all  catalytic  agents,  that 
is,  they  increase  the  speed  of  reaction.  In  the  case  of  such  a 
reaction  as  that  of  NaOH  and  HC1,  the  reaction  is  so  rapid 
that  the  effect  of  catalyzers  could  hardly  be  noticed  ;  but  with 


in  Ergebnisse  der  Physiol.,  1902   (Bd.  L,  Abt.  1),  p.  134;  also 
Bergell,  Zeit.  klin.  Med.,  1905  (57),  382. 
5 


66  ENZYMES 

many  other  substances  the  reaction  is  very  slow,  and  without 
the  presence  of  catalyzers  it  would  go  on  almost  or  quite 
imperceptibly.  For  example,  ethyl  butyrate  saponifies  on  the 
addition  of  water  according  to  the  following  equation  : 

C2H5-  O  -  OC  -  C3H7  +  H2O  ;±j:  C2H6OH  +  HOOC  -  C3H7. 

On  the  other  hand,  if  ethyl  alcohol  and  butyric  acid,  the  prod- 
ucts of  this  reaction,  are  placed  together,  they  will  combine  to 
form  ethyl  butyrate ;  in  other  words,  the  reaction  is  reversible, 
as  indicated  by  the  arrows  in  the  equation.  In  any  event, 
however,  the  reaction  is  not  complete,  but  continues  only  until 
a  certain  definite  proportion  of  ethyl  alcohol,  butyric  acid, 
ethyl  butyrate,  and  water  exists,  when  the  change  will  stop,  i.  e., 
equilibrium  is  established.  The  time  that  would  be  required  for 
this  reaction  to  occur  at  room  temperature  would  be  extremely 
long,  the  change  being  hardly  noticeable,  but  in  the  presence 
of  a  catalytic  agent  (which  may  be  colloidal  platinum  or 
lipase)  the  reaction  goes  on  much  more  rapidly.  Catalytic 
agents,  therefore,  merely  hasten  reactions  which  would  go  on 
without  them,  and  they  do  not  initiate  or  change  the  nature  of 
chemical  reactions  at  all.  When  equilibrium  is  established,  the 
reaction  stops  and  the  enzyme  has  nothing  more  to  do.  Further- 
more, and  this  is  a  recently  appreciated  fact,  enzymes  will  has- 
ten synthesis  just  as  well  as  they  hasten  catalysis.  Croft  Hill 
first  showed  that  maltase  would  synthesize  glucose  into  maltose ; 
Kastle  and  Loevenhart  soon  after  established  the  synthesis  of 
ethyl  butyrate  under  the  influence  of  lipase,  and  Neil  son l 
demonstrated  that  platinum  black  had  the  same  property. 
Taylor2  first  synthesized  one  of  the  normal  body  fats,  triolein, 
by  the  action  of  lipase  (from  the  castor-oil  bean)  upon  oleic  acid 
and  glycerin.  It  may  seem  improbable  at  first  sight  that  the 
synthesis  of  proteids  can  be  accomplished  by  enzymes,  as  is  the 
relatively  very  simple  synthesis  of  carbohydrates  and  fats,  but 
the  improbability  disappears  when  we  recall  the  well-known 
fact  that  the  products  of  proteid  splitting  in  passage  through 
the  intestinal  wall  disappear  and  are  reconverted  either  there  or 
elsewhere  into  body  proteids.  Proteids  manifestly  are  synthe- 
sized and  we  have  not  a  little  reason  to  believe  that  this  is 
accomplished  by  enzymes,  presumably  by  a  reversal  of  their 
action  in  the  establishment  of  equilibrium.  Taylor  was  unable 
to  synthesize  protamin,  one  of  the  simplest  proteids,  by  the 
action  of  trypsin  upon  its  cleavage  products,  but  it  has  been 

1  Amer.  Jour,  of  Physiol.,  1903  (10),  191. 

2  Univ.  of  California  Publications  (Pathology),  1904  (1),  33. 


THE  PRINCIPLES  OF  ENZYME  ACTION  67 

found  that  the  addition  of  proteolytic  enzymes  to  solutions  of 
pure  albumose  leads  to  the  formation  of  a  jelly-like,  insoluble 
proteid  substance,  which  seems  to  be  the  eifect  of  a  reversed 
action  on  the  part  of  the  enzymes.1  Indeed,  the  question  has 
been  raised  whether  the  coagulating  or  "  lab-ferment  "  (rennin) 
of  the  stomach  is  anything  more  than  the  pepsin  itself,  acting 
in  a  reverse  direction.2  Another  well-known  synthetic  action 
that  seems  to  be  due  to  reversible  ferment  action  is  the  forma- 
tion of  hippuric  acid  from  ben  zoic  acid  and  glycocoll  in  the 
kidney  ;  the  formation  of  glucose  into  glycogen  and  its  reforma- 
tion are  also  probably  both  accomplished  by  one  and  the  same 
enzyme  acting  reversibly.  Other  reversible  reactions  less 
closely  related  to  animal  cells  have  also  been  described. 

The  reversible  nature  of  enzyme  action  explains  many  prob- 
lems of  metabolism,  and  makes  the  whole  field  much  clearer. 
The  following  consideration  of  the  newer  understanding  of  fat 
metabolism  on  this  basis  may  explain  the  manner  in  which 
chemical  changes  are  believed  to  occur  in  the  cells  and  fluids 
of  the  body  :  3 

In  the  intestines  fat  is  split  by  lipase  into  a  mixture  of  fat,  fatty  acid,  and 
glycerin  ;  but  as  the  fatty  acid  and  glycerin  are  diffusible,  while  the  fat  is 
not,  they  are  separated  from  the  fat  by  absorption  into  the  wall  of  the  intes- 
tine. Hence  an  equilibrium  is  not  reached  in  the  intestine,  so  the  splitting 
continues  until  practically  all  the  fat  has  been  decomposed  and  the  products 
absorbed.  When  this  mixture  of  fatty  acid  and  glycerin  first  enters  the  epi- 
thelial cells  lining  the  intestines  there  is  no  equilibrium,  for  there  is  no  fat 
absorbed  with  them  as  such.  Therefore  the  lipase,  which  Kastle  and  Loeven- 
hart  showed  was  present  in  these  cells,  sets  about  to  establish  equilibrium  by 
combining  them.  As  a  result  we  have  in  the  cell  a  mixture  of  fat,  fatty  acid, 
and  glycerin,  which  will  attain  equilibrium  only  when  new  additions  of  the  two 
last  substances  cease  to  enter  the  cell.  Now  another  factor  also  appears,  for 
on  the  other  side  of  the  cell  is  the  tissue  fluid,  containing  relatively  little  fatty 
acid  and  glycerin.  Into  this  the  diffusible  contents  of  the  cell  will  tend  to  pass 
to  establish  an  osmotic  equilibrium,  which  is  quite  independent  of  the  chem- 
ical equilibrium.  This  abstraction  of  part  of  the  cell  contents  tends  to  again 
overthrow  chemical  equilibrium,  there  now  being  an  excess  of  fat  in  the  cell. 
Of  course,  the  lipase  will,  under  this  condition,  reverse  its  action  and  split  the 
fat  it  has  just  built  into  fatty  acid  and  glycerin.  It  is  evident  that  these  proc- 
esses are  all  going  on  together,  and  that,  as  the  composition  of  the  contents  of 
the  intestines  and  of  the  blood-vessels  varies,  the  direction  of  the  enzyme  action 
will  also  vary.  In  the  blood-serum,  and  also  in  the  lymphatic  fluid,  there  is 
more  lipase,  which  will  unite  part  of  the  fatty  acid  and  glycerin,  and  by  re- 
moving them  from  the  fluid  about  the  cells  favor  osmotic  diffusion  from  the 
intestinal  epithelium,  thus  facilitating  absorption. 

Quite  similar  must  be  the  process  that  takes  place  in  the  tissue  cells  through- 
out the  body.  In  the  blood-serum  bathing  the  cells  is  a  mixture  of  fat  and  its 

1  Herzog,  Zeit.  f.  physiol.  Chem.,  1903  (39),  305. 

2  The  results  of  filtration  experiments  suggest  that  pepsin  and  rennin  are 
distinct  substances  (Levy,  Jour.  Infect.  Diseases,  1905  (2),  1 ;  also  see  Schmidt- 
Nielsen,  Zeit.  physiol.  Chem.,  1906  (48),  92). 

3  See  Loevenhart,  Amer.  Jour,  of  Physiol.,  1902  (6),  331 ;  Wells,  Journal 
Amer.  Med.  Assoc.,  1902  (38),  220. 


68  ENZYMES 

constituents,  probably  nearly  in  equilibrium,  since  lipase  accompanies  them. 
If  the  diffusible  substances  enter  a  cell  containing  lipase,  e.  g.,  a  liver  cell,  the 
process  of  building  and  splitting  will  be  quite  the  same  as  in  the  intestinal  epi- 
thelium. The  only  difference  is  that  here  the  fatty  acid  may  be  removed 
from  the  cell  by  being  utilized  by  oxidation  or  some  other  chemical  transforma- 
tion. 

To  summarize,  it  may  be  stated  that  throughout  the  body 
there  is  constantly  taking  place  both  splitting  and  building  of 
fat.  Fat  enters  the  cells,  leaves  them,  and  is  utilized  only  in 
the  form  of  its  acid  and  alcohol,  never  as  the  fat  itself.  Fat 
constitutes  a  resting  stage  in  its  own  metabolism. 

If  proteolytic  enzymes  are  also  reversible,  then  the  phenom- 
ena of  proteid  metabolism  are  similarly  explained,  for  there 
is  no  doubt  that  every  cell  and  body  fluid  contains  proteolytic 
enzymes. 

All  metabolism,  then,  may  be  considered  as  a  continuous  at- 
tempt at  establishment  of  equilibrium  by  enzymes,  pet^petuated  by 
prevention  of  attainment  of  actual  equilibrium  through  destruction 
of  some  of  the  participating  substances  by  oxidation  or  other  chem- 
ical processes,  or  by  removal  from  the  cell  or  entrance  into  it  of 
materials  which  overbalance  one  side  of  the  equation. 

In  just  what  manner  the  enzymes  accomplish  their  catalytic 
effect  is  yet  unknown.  A  favorite  idea  is  that  they  form  loose 
compounds  with  the  body  to  be  split  and  with  water  ;  the  result- 
ing compound  being  unstable  and  breaking  down,  the  water 
remaining  attached  to  the  components  of  the  substance.  There 
is  some  evidence,  but  not  conclusive,  indicating  that  the  enzyme 
does  enter  into  combination  with  its  object.  Euler  has  suggested 
that  enzymes  increase  ionization,  which  is  at  the  bottom  of  the 
chemical  changes. 

Enzymes  do  not  act  catalytically  on  all  substances  by  any 
means,  but  show  a  decidedly  specific  nature.  They  affect  only 
organic  substances,  and  the  actions  are  limited  to  two  processes — 
hydrolysis  and  oxidation,  or  the  reverse  processes  of  dehydration 
and  reduction. 1  The  most  essential  difference  between  the 
enzymes  and  the  chemicals  that  can  accomplish  hydrolysis  or 
oxidation  is  this  :  the  ordinary  chemical  reagents  produce  their 
effects  on  many  sorts  of  substance,  the  enzymes  are  specific; 
thus  hydrochloric  acid  will  hydrolyze  starch  or  proteid  with 
equal  facility,  but  pepsin  will  not  affect  starch  at  all. 

The  very  specific  nature  of  the  enzymes,  their  activation  by 
other  body  products,  the  fact  that  they  seem  to  be  bound  to  the 
substance  upon  which  they  act,  that  they  are  susceptible  to  heat, 

J  Alcoholic  fermentation  may  be  an  exception,  the  change  being  C6H12O6  = 
2C2H5OH  +  2CO2,  but  it  is  very  possibly  an  intramolecular  oxidation. 


THE  PRINCIPLES  OF  ENZYME  ACTION  69 

and  that  they  produce  immune  bodies  when  injected  into  exper- 
imental animals,  all  suggests  the  probability  of  a  relationship 
between  enzymes  and  toxins.  This  matter  will  be  discussed  more 
fully  in  considering  the  chemistry  of  immunity  against  enzymes. 

General  Properties  of  Enzymes. — Other  properties  of 
enzymes  may  be  briefly  mentioned.  The  speed  of  reaction  they 
produce  increases  with  the  amount  of  enzyme  present,  but  not 
in  direct  proportion  (except  with  rennin).  Very  dilute  acids 
favor  the  action  of  nearly  all  ferments,  and  alkalies  are  unfa- 
vorable for  all  but  trypsin,  ptyalin,  and  a  few  others.  Weak 
salt  solutions  also  are  more  favorable  than  distilled  water. 
(These  facts  suggest  strongly  the  possibility  that  ions  play  an 
important  role  in  the  process.)  Water  and  dilute  glycerin  dis- 
solve enzymes,  which  form  always  colloidal  solutions  that  are 
very  slightly  dialyzable  ;  and  they  may  be  precipitated  from 
solution  by  alcohol,  and  redissolved  again  with  but  slight  im- 
pairment of  strength.  Filtration  through  porcelain  filters  is 
not  complete,  from  10  to  25  per  cent,  of  most  enzymes  being 
lost  in  each  filtration.  *  As  before  mentioned,  many  chemicals 
poisonous  to  bacteria  have  little  influence  on  most  enzymes,  but 
nearly  all  substances  when  concentrated  are  injurious  or  destruc- 
tive, and  some  enzymes  are  known  that  are  more  susceptible  to 
antiseptics  than  are  the  cells  that  contain  them.  Formaldehyde 
is  very  destructive  to  enzymes,  even  when  dilute.  The  effect  of 
proteid-coagulating  antiseptics  upon  enzymes  is,  of  course, 
greatly  modified  by  the  amount  of  proteid  substances  mingled 
with  the  enzymes  ;  and  the  effects  of  heat  and  other  injurious 
influences  are  greatly  decreased  by  the  presence  of  proteids  and 
other  impurities. 

All  enzymes  are  most  active  between  35°  and  45°  C.,  and  it 
is  interesting  to  note  that  Robert 2  found  this  equally  true  for 
enzymes  derived  from  cold-blooded  animals.  Although  enzymes 
can  stand  temperatures  of  100°  C.  or  more  when  dry,  in  water 
they  are  generally  destroyed  somewhat  below  70°  C.  Low  tem- 
perature, even — 190°  C.,3  (liquid  air),  does  not  destroy  them. 
The  loss  of  power  through  heating  disappears  gradually,  and 
there  is  no  sharp  line  at  which  their  action  disappears.  Sun- 
light is  harmful  to  enzymes  in  solution,  but  only  in  the  presence 
of  oxygen 4 ;  this  effect  is  augmented  by  the  presence  of  fluo- 
rescent substances.  Radium  and  arrays  seem  to  have  a  dele- 

1  Literature,  see  Levy,  Jour.  Infectious  Diseases,  1905  (2),  1. 

2  Pfliiger's  Arch.,  1903  (99),  116. 

3  Bickel,  Dent.  med.  Woch.,  1905  (31),  1383. 

4  lodlbauer  and  Tappeiner,  Deut.  Arch.  klin.  Med.,  1905  (85),  386. 


70  ENZYMES 

terious  effect  upon  most  enzymes,  and  retard  their  rate  of  action  ; 
but,  apparently,  autolytic  enzymes  (Neuberg  l )  and  tyrosinase 
(Willcock 2  )  are  not  injured  by  these  agencies.  Labile  as  enzymes 
are,  their  persistence  when  dry  is  remarkable  ;  Kobert  found 
active  trypsin  in  the  bodies  of  spiders  that  had  been  in  the 
Nuremberg  Museum  for  150  years,  andSehrt3  found  that  the 
muscle  tissue  of  mummies  contained  active  glycolytic  ferment. 

All  enzymes  as  ordinarily  prepared  have  the  property  of 
decomposing  hydrogen  peroxide,  a  property  possessed  by  sub- 
stances of  varied  nature;  this  effect  is  prevented  by  CNH, 
which  does  not  prevent  other  enzyme  manifestations,  indicating 
that  this  property  is  due  to  an  associated  enzyme,  catalase. 

The  retardation  of  enzyme  action  by  accumulation  of  the 
products  of  their  action  is  simply  explained  as  being  due  to 
establishment  of  equilibrium;  in  some  instances,  however,  the 
substances  produced  are  of  themselves  harmful  to  the  enzymes, 
e.  </.,  alcohol  and  acetic  acid. 

Activation  of  Enzymes. — Within  the  cell,  the  enzymes — at 
least  those  that  are  excreted,  such  as  trypsin  and  pepsin — exist 
with  few  exceptions  in  an  inactive  form,  the  zymogen.  Their 
activation  appears  to  take  place  normally  only  after  they  have 
been  discharged  from  the  cell,  but  after  the  death  of  an  organ 
it  may  result  from  the  decomposition  products  that  are  formed. 
Under  physiological  conditions  this  activation  appears  to  be 
brought  about  by  special  activating  substances.  In  the  case  of  the 
pancreas  it  is  the  enterokinase,  which  is  furnished  by  the  epithe- 
lial cells  of  the  intestine.  Enterokinase  appears  to  unite  with 
trypsinogen  to  form  an  active  enzyme,  which  reminds  one  of  the 
way  that  complement  and  the  intermediary  body  unite  to  form 
hemolytic  and  bacteriolytic  substances.4  Kinases,  having  the 
same  action  as  enterokinase  upon  the  trypsinogen,  are  found  in 
various  tissues  and  organs,  but  generally  much  less  active  than 
the  enterokinase.  Pepsinogen  is  probably  activated  by  the  HC1 
of  the  gastric  juice.  A  similar  activating  process  seems  to  be 
essential  for  the  production  of  the  glycolytic  ferment  of  the 
muscle  and  liver,  the  pancreas  furnishing  the  activator  in  this 
<case.  It  is  very  probable  that  it  is  through  this  mechanism 

'  *  Berl.  klin.  Woch.,  1904  (41),  1081. 

2  Jour,  of  Physiol.,  1906  (34),  207. 

3  Berl.  klin.  Woch.,  1904  (41),  497. 

•*  Bayliss  and  Starling  (Jour,  of  Physiol.,  1905  (32),  129),  question  the  anal- 
ogy of  zymogen-kinase  combinations  to  complement-amboceptor  combination. 
Walker,  however,  finds  evidence  that  many  enzymes  consist  of  a  specific  ambo- 
ceptor  and  a  non-specific  complement  or  kinase  (Jour,  of  Physiol.,  1906  (33), 
p.  xxi.). 


THE  TOXICITY  OF  ENZYMES  71 

that  the  rate  of  enzyme  action  is  modified,  and  perhaps  it  is  a 
means  of  defense  of  the  body  against  its  own  enzymes ;  as  the 
prozymes  are  more  resistant  to  harmful  agencies  than  the 
enzymes,  it  also  may  be  a  method  of  storage. 

THE  TOXICITY  OF  ENZYMES 

Although  present  normally  in  greater  or  less  amounts  in  all 
the  cells  in  the  body,  when  artificially  isolated  and  injected 
directly  into  animals  nearly  all  enzymes  seem  to  be  extremely 
toxic.  The  first  thorough  study  of  the  toxicity  of  enzymes  was 
made  by  Hildebrandt,1  who  found  that  pepsin,  invertase,  dias- 
tase, emulsin,  myrosin,  and  rennin  were  all  toxic.  Emulsin 
and  myrosin  were  most  toxic,  0.05  gram  being  the  lethal 
dose  for  a  rabbit  (average  size)  ;  for  pepsin,  invertase,  and  dias- 
tase the  lethal  dose  was  0.1  gram,  while  rennin  required  2 
grams.  The  symptoms  produced  in  dogs  were  trembling, 
uneasiness,  difficulty  in  walking,  and  finally  coma.  The  ana- 
tomical changes  observed  were :  numerous  hemorrhages  through- 
out the  body,  fatty  degeneration  of  the  liver  and  myocar- 
dium, renal  congestion,  and  numerous  thromboses.  Consid- 
erable fever  results,  and  Mayer  considers  this  responsible  for 
the  relative  harmlessness  of  rennin,  the  action  of  which  is 
impaired  above  40°.  That  these  effects  are  due  to  the  enzymes 
themselves  rather  than  to  contaminating  bacteria  is  shown  by 
Kionka  and  by  Achalme 2  who  obtained  similar  results  with 
enzymes  made  sterile  by  filtration  through  porcelain.  Achalme 
found  that  such  sterile  preparations  of  pancreatic  juice  injected 
subcutaneously  into  guinea-pigs  produce  a  marked  local  pink 
gelatinous  edema,  followed  by  gangrene  ;  if  the  animal  dies,  the 
blood  is  non-coagulable.  Intraperitoneal  injection  is  better 
withstood  than  subcutaneous.  Fiquet 3  also  observed  that  tryp- 
sin  and  pepsin  rendered  the  blood  incoagulable,  but  after  some 
time  the  coagulability  of  the  blood  is  increased  and  thrombosis 
is  frequent.  Wells 4  found  that  pancreatic  extracts  containing 
very  active  trypsin  and  lipase  injected  intraperitoneally  pro- 
duced an  acute  inflammatory  reaction,  but  no  fat  necrosis. 
Extracts  containing  active  lipase  and  inactive  trypsin  were  less 
toxic,  but  produced  fat  necrosis.  Extracts  of  liver  and  blood- 
serum,  rich  in  lipase,  were  almost  without  effect  on  dogs  and  cats. 
Papain  was  found  to  be  much  more  toxic  than  any  animal 

1  Virchow's  Archiv,  1890  (121),  1. 

2  Ann.  d.  1  'Inst.  Pasteur,  1901  (15),  737. 

3  Arch.  d.  M£d.  Exper.,  1899  (11),  145. 

4  Jour.  Med.  Eesearch,  1903  (9),  92. 


72  ENZYMES 

enzyme,  causing  violent  local  hemorrhagic  inflammation.  Schep- 
ilewsky  1  also  found  papain  much  more  toxic  than  rennin  and 
pancreatin;  repeated  injection  of  the  two  latter  caused  amyloid- 
osis  in  rabbits.  Lombroso 2  found  that  inactive  pancreatic  juice 
was  much  less  toxic  than  the  activated,  showing  that  it  is 
the  trypsin  that  is  the  important  toxic  agent.  He  also  found 
that  succus  entericus  in  doses  of  1  to  5  c.c.  is  toxic,  but  not 
lethal  for  dogs.  Hildebrandt3  observed  that  enzymes  were 
positively  chemotactic,  but  it  is  probable  that  the  products  of 
their  action  on  the  tissues  are  the  chief  chemotactic  agents. 

The  enzymes  that  are  secreted  into  the  gastro-intestinal  tract 
seem  to  be  chiefly  destroyed,  but  part  is  eliminated  in  the  feces, 
and  part  that  is  absorbed  apparently  reappears  in  the  urine  in 
very  small  quantities.  Pepsin,  diastase,  and  rennin  all  have 
been  found  in  normal  urine ;  but  the  occurrence  of  trypsin  is 
unsettled.  Zeri4  could  find  no  lipase  in  normal  or  nephritic 
urine,  except  when  blood  or  leucocytes  were  present.  Fer- 
ments injected  stibcutaneously  seem  seldom  to  be  eliminated  in 
any  considerable  amounts  in  the  urine,  but  Opie5  has  demon- 
strated the  presence  of  lipase  in  the  urine  in  pancreatitis  with 
fat  necrosis.  Hildebrandt  was  able  to  prove  that  emulsin 
remained  active  for  at  least  six  hours  a^'ter  it  was  injected 
into  animals  subcutaneously,  by  its  splitting  amygdalin  which 
was  then  injected,  the  CNH  liberated  by  the  cleavage  of  the 
amygdalin  causing  death. 

Anti-enzymes. — Injection  of  enzymes  into  animals  leads  to 
the  appearance  of  substances  in  the  serum  of  the  animals  that 
antagonize  the  action  of  the  enzymes.  The  principles  involved 
are  quite  the  same  as  in  the  immunization  of  animals  against 
bacterial  toxins  or  against  foreign  proteids.  This  seems  to  have 
been  first  observed  by  Hildebraudt,  and  it  has  been  taken  up 
extensively  in  recent  years  in  the  study  of  the  problems  of 
immunity.  An  interesting  observation  that  was  made  rather 
early  in  these  studies  was  that  normal  blood-serum  possesses  a 
marked  resistance  against  the  action  of  proteolytic  enzymes,  not 
being  at  all  digested  by  dilutions  of  enzymes  that  will  rapidly 
digest  a  serum  that  has  been  heated  This  property  seems  to  be 
shared  by  egg-white  and  by  the  tissues  and  organs  of  the  body 
(Levene  and  Stookey 6 ).  The  anti-enzyme  action  seems  to  be 

1  Cent.  f.  Bakt.,  1899  (25),  849. 
Abstract  in  Biochem.  Centralblatt,  1903  (1),  712. 
Virchow's  Arch.,  1893  (131),  5. 
II  Policlinico,  1905  (12),  733. 
Johns  Hopkins  Hosp.  Bull.,  1902  (13),  117. 
Jour.  Medical  Research,  1903  (10),  217. 


ANTI-ENZYMES  73 

easily  destroyed,  by  heat  of  about  70°,  by  the  action  of  dilute 
acids,  and  even  by  prolonged  standing.  It  is  exerted  not  only 
against  the  secreted  proteolytic  enzymes,  pepsin  and  trypsiu, 
but  also  against  the  intracellular  enzymes  of  various  organs. 

It  seems  highly  probable  that  the  resistance  of  the  body  tis- 
sues to  digestion  by  their  own  enzymes  and  by  the  enzymes  of 
one  another  depends  in  some  way  upon  the  presence  of  anti- 
enzymes  in  the  cells  and  tissue  fluids.  Weinland  [  has  demon- 
strated that  certain  intestinal  worms  contain  a  strong  antitryp- 
sin, to  which  he  attributes  their  ability  to  live  bathed  in  pancre- 
atic juice  without  being  digested.  Similar  properties  have  been 
ascribed  by  other  observers  to  the  cells  of  the  mucosa  of  the 
stomach 2  and  intestine.  An  anti-catalase  has  been  described  as 
present  in  the  tissues  of  the  body  by  Battelli  and  Stern. 3  The 
anti-enzymes  seem  only  to  inhibit  enzyme  action,  and  not  to 
destroy  the  enzyme  itself.4  Normal  anti-enzymes  do  not  seem 
to  be  at  all  specific,  according  to  v.  Eisler,5  that  is,  human  serum 
is  no  more  resistant  to  human  trypsin  than  is  pig  serum — indeed, 
it  is  less  so.6 

Cathcart7  believes  that  antitrypsin  is  connected  with  the 
" albumin  fraction"  of  the  serum,  i.  e.,  the  fraction  precipitated 
between  half  and  full  saturation  with  ammonium  sulphate. 
Globulins  do  not  possess  this  action,  but  they  are  not  easily 
digested.  He  found  antitrypsin  in  all  varieties  of  serum,  and 
considers  it  little  or  not  at  all  specific.  It  is  destroyed 
by  55  °C.8  for  one-half  hour,  but  retains  its  anti-enzymatic 
activity  after  drying.  The  isolated  body  is  equally  effective 
against  all  sorts  of  proteids.  Glaessner 9  claims  that  the  anti- 
trypsin is  united  to  the  euglobulin  fraction  of  the  blood-serum, 
and  that  it  is  most  abundant  during  periods  of  digestion.  Fuld 
and  Spiro 10  found  that  the  natural  antirennin  of  normal  horse 

1  Zeit.  f.  Biol.,  1903  (44),  45  ;  see  also  Dastre  and  Stassano,  Compt.  Rend. 
Soc.  Biol.,  1903  (55),  130  and  254 ;  and  Hamill,  Jour,  of  Physiol.,  1906  (33), 

2  See  Blum  and  Fuld,  Zeit.  klin.  Med.,  1906  (58),  505. 

3  Jour.  Phys.  et  Path,  gen,  1905  (7),  919. 

4  According  to  Delezenne  and  others,  antitrypsin  exerts  its  effects  chiefly  by 
combining  with  the  kinase  that  activates  trypsinogen,  rather  than  with  the  tryp- 
sin.    Bayliss  and  Starling  (Jour,  of  Physiol.,  1905  (32),  129)  oppose  the  view 
of  Delezenne  that  the  antitryptic  action  of  the  blood  is  due  to  an  antikinase, 
and  believe  the  antibody  acts  upon  trypsin. 

5  Ber.  d.  Wien.  Akad.,  1905  (104),  ]19. 

6  This  is  contradicted  by  Glaessner  (loc.  cit.). 

7  Jour,  of  Physiol.,  1904  (31),  497. 

8  Unless  otherwise  specified,  all  temperatures  are  given  according  to  the 
Centigrade  scale. 

9  Hofmeister's  Beitriige,  1903  (4),  79. 

10  Zeit.  f.  physiol.  Chern.,  1900  (31),  132. 


74  ENZYMES 

serum  is  in  the  pseudoglobulin  fraction.  Since  acids  destroy 
the  anti-enzyme  property  of  the  serum,  it  is  not  effective  against 
pepsin-HCl  mixtures.  Against  trypsin,  however,  it  is  very 
effective.  Red  corpuscles  and  living  unicellular  organisms  are 
likewise  resistant  to  trypsin,  and  normal  serum  also  seems  to 
contain  an  antirennin. l 

Oppenheimer  and  Aron 2  consider  it  probable  that  the  resist 
tance  of  normal  serum  to  trypsin  digestion  depends  upon  the 
configuration  of  the  proteid  molecules,  which  perhaps,  when  in 
fresh,  uninjured  condition,  present  no  suitable  surfaces  for 
attack  by  the  ferment. 

Opie3  has  found  that  the  serum  of  inflammatory  exudates 
contains  an  anti-enzymatic  substance,  destroyed  at  75°,  and  by 
acids. 

Ascoli  and  Bezzola 4  state  that  the  antitryptic  action  of  the 
blood  is  increased  during  pneumonia,  which  is  probably  the 
result  of  a  self-immunization  against  the  ferments  liberated  by 
the  disintegrated  leucocytes.5 

The  anti-enzymatic  property  obtained  in  the  serum  by  inject- 
ing enzymes  into  animals  differs  from  that  normally  present  in 
the  serum  in  many  ways.  It  may  be  made  much  stronger 
than  it  ever  is  in  normal  serum,  and  against  many  varieties  of 
enzymes  for  which  an  anti-enzyme  does  not  naturally  exist. 
Especially  important  is  the  fact  that  it  is  highly  specific  (v. 
Eisler) ;  serum  of  an  animal  immunized  against  dog  trypsin 
will  show  a  much  greater  effect  against  dog  trypsin  than  it  does 
against  trypsin  from  other  animals.  This  fact  permits  us  to 
distinguish  between  enzymes  of  apparently  similar  nature  but 
of  different  origin,  and  proves  that  they  have  a  structure  at 
least  in  some  respects  different  from  one  another,  since  they  are 
combined  by  different  antibodies.  Artificial  immune  serum 
has  been  obtained  against  trypsin,  pepsin,  lipase,  emulsin,  auto- 
lytic  enzymes,  tyrosinase,  urease,  rennin,  catalase,  and  fibrin  fer- 
ment. 6  By  immunization  against  bacteria  an  immunity  against 
their  proteolytic  enzymes  is  also  obtained/ 

1  Czapek  (Ber.  Deut.  botan.  Gesell.,  1903  (21),  229,  states  that  anti-oxidases 
occur  normally  in  certain  plants,  strongly  specific  against  the  oxidase  of  the 
same  plant  species. 

2  Hofrneister's  Beitrage,  1903  (4),  279. 

3  Jour.  Exp.  Med.,  1905  (7),  316. 

4  Berl.  klin.  Woch.,  1903  (40),  391. 

5  Beitzke  and  Neuberg  (  Virch.  Arch.,  1906  (183),  169)  have  suggested 
that  anti-enzymes  may  act  by  causing  a  synthesis  that  opposes  the  catalysis  of 
the  enzyme. 

6  For  a  review  of  much  of  the  literature  on  this  subject  see  Schiitze,  Deut. 
med.  Woch.,  1904  (30),  308. 

7  v.  Dungern,   Munch,  med.  Wochenschr.,  1898  (45),  1040. 


THE  INTRACELLULAR  ENZYMES  75 

Resemblances  of  Enzymes  and  Toxins. — As  can  be  seen 
from  the  above  statements,  the  enzymes  behave  in  many 
respects  like  the  toxins,  both  in  their  manner  of  acting  upon 
other  substances  and  in  the  reaction  they  produce  when  intro- 
duced into  the  bodies  of  animals.  As  Oppenheimer  says,  "  the 
bonds  between  enzymes  and  toxins  are  drawing  closer  and 
closer."  According  to  some  experiments,  the  enzymes  behave 
much  as  if  they  possessed  a  haptophore  and  a  toxophore  group, 
the  former  of  which  combines  with  the  substance  that  is  to  be 
acted  upon ;  and  immunity  appears  to  be  produced  by  the 
development  of  receptors  that  combine  the  haptophore  groups, 
these  receptors  constituting  the  antiferments.  Korschun  1  has 
even  succeeded  in  obtaining  an  anti-antirennin.  He  also  secured 
rennin  in  an  altered  condition  so  that  it  did  not  coagulate  milk, 
but  still  did  unite  with  antirennin — a  "  fermentoid,"  according 
to  the  Ehrlich  nomenclature.  This  is  a  strong  piece  of  evidence 
of  the  similarity  of  enzymes  and  toxins.  On  the  other  hand,  an 
important  difference  between  the  enzymes  and  the  toxins  is  that 
toxins  produce  their  effects  according  to  the  law  of  definite 
proportions,  which  is  quite  different  from  the  behavior  of  cata- 
lyzing agents.  Also  some  of  the  toxins  have  greater  heat 
resistance  than  most  enzymes,  whereas  complement  is  more 
easily  destroyed  than  are  the  enzymes. 2 

THE   INTRACELLULAR   ENZYMES 

Until  a  very  recent  time  our  knowledge  of  enzymes  in  the  ani- 
mal body  was  limited  to  those  present  in  the  digestive  secretions. 
With  few  exceptions  these  are  without  influence  in  pathological 
processes,  since  they  seem  to  be  but  little  absorbed,  and  rarely 
^nter  the  blood  or  tissue  in  any  other  way.  But  with  the  more 
recently  disclosed  intracellular  enzymes,  many  of  which  are 
present  in  every  cell,  the  relation  to  pathology  is  very  intimate. 
These  intracellular  enzymes,  as  we  now  know  them,  and  their 
chief  properties,  are  as  follows  : 

OXIDIZING  ENZYMES 

Although  oxidation  of  organic  compounds  is  the  chief  source 
of  energy  in  the  animal  body,  yet  the  way  in  which  it  is  accom- 
plished is  very  little  understood.  We  only  know  that  it  is 
brought  about  within  the  cells,3  and  that  substances  that  out- 

1  Zeit.  f.  physiol.  Chem.,  1902  (36),  141 ;  1903  (37),  366. 

2  The  supposed  relationship  of  enzymes  and  toxins  is  questioned  by  Lieber- 
mann,  Deut.  med.  Woch.,  1905  (31)r  1301. 

3Lillie  (Amer.  Jour,  of  Physiol.,  1902  (7)  412,  has  demonstrated  that 
oxidation  occurs  chiefly  about  or  within  the  nucleus. 


76  ENZYMES 

side  the  body  are  oxidized  with  difficulty,  are  completely  oxi- 
dized to  carbon  dioxide  and  water  within  the  cells,  and  that  this 
is  done  with  just  such  a  degree  of  rapidity  that  the  heat  pro- 
duced is  in  exactly  the  amount  necessary  for  the  wants  of  the 
body. l  There  can  be  little  question  that  this  oxidation  is 
accomplished  through  catalytic  agents  acting  within  the  cells, 
and  certain  of  them  have  been  placed  in  a  condition  permitting 
of  study.  As  yet  their  exact  relations  to  intracellular  oxidation 
are  not  clearly  defined,  but  for  the  present  they  may  be  grouped 
provisionally  as  oxidizing  enzymes.  One  of  the  most  studied 
of  these  is — 

Catalase. — It  has  long  been  known  that  most  enzymes  pos- 
sess the  power  of  decomposing  hydrogen  peroxide,  with  libera- 
tion of  oxygen;  but  it  was  not  until  1901  that  it  was  finally 
demonstrated  by  Loew 2  that  this  property  was  due  to  a  separate 
enzyme  and  was  independent  of  the  specific  properties  of  the 
various  other  enzymes. s  This  ferment  is  very  wide-spread,  and 
so  is  generally  obtained  along  with  the  other  enzymes  when 
attempts  are  made  to  isolate  them  from  the  cell.  It  was  named 
catalase  by  Loew,  and  he  described  two  forms,  a-catalase,  which 
seems  to  be  a  nucleoproteid,  and  fi-catalase,  which  has  the 
properties  of  an  albumose.  It  has  been  demonstrated  by  Bach 
and  Chodat4  that  peroxides  are  contained  in  plant  cells,  and 
from  the  wide  distribution  of  catalase  it  seems  probable  that 
they  also  occur  in  animal  cells.  Just  what  function  the  catalase 
performs  is  at  present  merely  a  matter  of  speculation.  Loew 
considers  that  it  destroys  peroxides  formed  in  metabolism,  which 
are  very  poisonous  to  cell  life.  Shaffer 5  has  found  evidence 
that  under  the  influence  of  catalase  the  oxygen  liberated  is  in 
the  molecular  form,  O2,  and  therefore  relatively  inert ;  whereas 
when  peroxides  spontaneously  decompose,  they  liberate  atomic 
oxygen  which  is  an  active  oxidizing  agent.  He  found  that  uric 
acid  is  oxidized  by  peroxide  of  hydrogen,  but  when  catalase  is 
present,  this  oxidation  is  prevented.  According  to  this  the  func- 
tion of  catalase  is  rather  to  prevent  dangerous  forms  of  oxida- 
tion than  to  help  in  normal  oxidative  processes.  For  the 
present,  however,  nothing  can  be  said  positively  on  this 
subject. 

1  A  full  discussion  of  this  subject  is  given  by  Hammarsten,  "  Physiological 
Chemistry, "  introductory  chapter. 

2  Keport  No.  68,  U.  S/Dept.  of  Agriculture. 

3  Other  observers  had  previously  suggested  the  same  possibility,  and  Jacob- 
son  had  proved  the  independence  of  catalase  action. 

4  Berichte  der  chem.  Gesellsch.,  Vols.  35  and  36 :  several  articles. 

5  Amer.  Jour,  of  Physiol.,  1905  (14),  300. 


CATALASE  77 

Occurrence  of  Catalase  under  Normal  and  Pathological  Condi- 
tions.— Battelli  and  Stern  *  in  one  of  the  most  recent  studies  have 
found  that  the  catalytic  power  of  the  tissues  endures  many  hours 
after  death.  Its  abundance  is  different  for  different  organs  of  the 
same  animal,  but  remarkably  constant  for  the  same  organ  in  the 
same  species.  In  general  the  order  in  decreasing  strength  is :  liver, 
kidney,  blood,  spleen,  gastro-intestinal  mucosa,  salivary  glands, 
lung,  pancreas,  testicle,  heart,  muscle,  brain;  but  this  order 
varies  in  different  species.  In  embryos  catalase  is  scanty,  but 
it  increases  rapidly  after  birth.  Leucocytes  contain  little,  most 
of  that  in  the  blood  being  in  the  stroma  of  the  red  blood-corpus- 
cles. The  body  fluids  contain  little  or  none.  Acute  poisoning 
by  phosphorus  or  CNH,  icterus,  and  double  nephrectomy  do 
not  reduce  the  amount  in  the  tissues  ;  in  chronic  phosphorus 
poisoning  the  amount  of  catalase  in  the  degenerated  liver  is 
decreased,  but  it  is  increased  in  the  other  organs.  Injected 
intravenously,  catalase  (of  the  liver)  is  destroyed  rapidly,  and 
does  not  appear  in  the  urine;  it  does  not  cause  any  toxic  effects, 
nor  does  it  increase  resistance  to  poisoning  by  venoms.  The 
tissues  also  contain  anti-catalases,  and  still  further  a  substance 
which  protects  the  catalase  from  the  anti-catalase ;  this  protec- 
tive substance  is  called  the  philocatalase  by  Battelli  and  Stern.2 
Jolles  and  Oppenheimer3  devised  methods  for  quantitative 
estimation  of  the  catalase  of  the  blood,  and  found  that  it  might 
be  considerably  reduced  in  diseases  (nephritis,  tuberculosis,  and 
carcinoma,  but  not  in  diabetes),  but  the  results  were  quite  incon- 
stant in  each  condition.  Carbon  monoxide  poisoning  did  not 
lower  the  catalase  action,  and  there  is  no  difference  between 
arterial  and  venous  blood  in  the  amount  of  catalase.  The  cata- 
lase action  is  independent  of  the  hemoglobin,  and  it  is  not  re- 
sponsible for  the  formation  of  oxyhemoglobin ;  it  is  much  less 
abundant  in  amphibia  than  in  man. 

The  gas  evolved  by  the  action  of  pus  on  H2O2  was  found  by 
Marshall 4  to  be  pure  oxygen,  each  c.c.  of  a  certain  sample  of 
pus  examined  liberating  133.9  c.c  of  gas.  The  active  constit- 
uent of  pus,  he  states,  is  contained  in  the  serum  and  not  in  the 
corpuscles. 

Substances  decomposing  H2O2  have  been  found  also  in  bac- 
terial cultures,  first  by  Gottstein,  and  later  in  the  cell-juices 


1  Archivio  di  Fisiologia,  1905  (2),  471.   This  article  contains  a  complete 
sume  of  the  literature  to  date  (in  French). 

*  Jour,  physiol.  et  path.  ge*n.,  1905  (7),  919  and  957. 

3  Virchow's  Arch.,  1905  (180),  185. 

4  Univ.  of  Penn.  Med.  Bull.,  1902  (15),  366. 


78  ENZYMES 

expressed  from  tubercle  bacilli  by  Hahn.  Loewenstein  l  found 
an  enzyme  agreeing  with  catalase  in  filtered  bouillon  cultures 
of  diphtheria  bacilli  and  staphylococci  but  not  from  tetanus, 
typhoid,  and  colon  bacilli  or  cholera  vibrios ;  the  catalase  is 
quite  distinct  from  the  toxin.  He  also  found  that  the  addition 
of  H2O2  to  a  diphtheria  toxin-antitoxin  mixture  destroyed  the 
toxin,  leaving  the  antitoxin  free.  A  similar  destruction  of 
tetanus  toxin  by  peroxides,  first  demonstrated  by  Sieber,  can 
occur  without  the  catalase. 

True  Oxidising  Enzymes. — While  it  is  by  no  means  cer- 
tain that  catalase  is  active  in  causing  intracellular  oxidations, 
there  are  a  number  of  other  enzymes  or  enzyme-like  substances 
that  come  more  properly  under  the  head  of  oxidases  or  oxidizing 
enzyme.  Those  so  far  studied  are  : 

Peroxidase. — This  name  is  given  to  an  enzyme  that  is  be- 
lieved to  cause  oxidation  by  activating  peroxides,  and  is  quite 
distinct  from  catalase  and  from  the  other  oxidases.  The  peroxide 
on  which  they  chiefly  act  in  the  cell  is  supposed  by  Bach  and 
Chodat 2  to  be  the  enzyme  oxygenase. 

Oxygenase. — This  enzyme  can  also  act  as  an  oxidizer  in- 
dependent of  the  peroxidase,  in  the  presence  of  certain  manganese 
compounds.  Loevenhart  and  Kastle 3  question  the  true  enzyme 
nature  of  this  and  other  "  oxidases,"  which  they  look  upon  as 
organic  peroxides,  behaving  like  other  peroxides  rather  than  as 
catalyzers.  Practically  the  knowledge  of  these  bodies  is  demon- 
strated by  their  power  to  turn  tincture  of  guaiac  blue,  and  they 
are,  therefore,  present  in  pus. 

By  their  conception  of  oxygenase  and  peroxidase  Chodat  and 
Bach  would  displace  entirely  the  idea  of  enzymes  oxidizing 
directly,  the  true  "  oxidases/7  which  they  consider  mixtures  of 
oxygenase  and  peroxidase.  How  far  this  is  justifiable  may 
well  be  questioned.  There  have  been,  in  any  event,  a  number 
of  ferments  described  that  seem  to  possess  distinct  oxidative 
powers.  As  each  is  quite  specific  in  its  action,  oxidizing  but 
one  substance,  or  one  group  of  related  substances,  they  are 
generally  designated  by  the  name  of  the  substances  upon  which 
they  act.  Most  studied  of  these  is — 

Aldehydase,  which  is  characterized  by.  oxidizing  aldehydes, 
particularly  salicyl-aldehyde.  According  to  Jacquet,  this  enzyme 

1  Wien.  klin.  Woch.,  1903  (16),  1393. 

2  Biochem.  Centralblatt,  1903  (1),  417  and  457,  where  is  also  given  a  re'sume' 
of  the  literature. 

3  Amer.  Chera.  Jour.,  1903  (29),  563. 


TYKOSINASE  79 

is  so  intimately  bound  with  the  cell  that  it  cannot  be  obtained 
in  extracts  until  after  the  cells  are  dead,  but  is  present  in  ex- 
pressed cell-juices.  It  can  be  isolated  by  the  usual  methods,  is 
destroyed  by  boiling,  and  its  action  is  inhibited  by  CNH.  It 
has  been  demonstrated  in  nearly  all  organs  and  tissues  except 
pancreas,  muscle,  marrow,  and  mammary  gland ;  it  is  present 
in  the  blood  in  small  amounts,  but  not  at  all  in  the  bile  (Jaco- 
by 1 ).  It  is  most  abundant  in  the  liver  and  spleen,  and  is 
present  in  pig  embryos,  9  cm.  long,  but  not  in  those  2-3  cm. 
long.  Jacoby  has  obtained  a  body  with  the  properties  of  alde- 
hydase  which  did  not  give  proteid  reactions.  It  is  a  true 
enzyme,  since  it  oxidizes  aldehydes  without  itself  being  used  up. 
Its  range  of  action  is  limited,  for  Jacoby  found  it  without 
effect  upon  acetic  acid  and  stearic  acid. 

Tyrosinase. — This  enzyme,  which  is  found  both  in  animal 
and  plant  tissues,  is  particularly  interesting  in  relation  to  the 
formation  of  pigments.  Bertrand  found  that  the  transformation 
of  the  juice  of  lac-yielding  plants  into  the  black  lacquer  was 
brought  about  by  the  action  of  an  oxidizing  ferment,  laccase, 
upon  an  easily  oxidized  substance,  laccol,  which  is  a  member  of 
the  aromatic  series.  He  later  found  in  a  number  of  plants  an 
enzyme  acting  on  ty rosin,  distinct  from  the  laccase,  which  he 
named  tyrosinase.  Biederman2  later  found  tyrosinase  in  the 
intestinal  fluid  of  meal  worms,  v.  Fiirth  and  Schneider 3  found 
a  similar  enzyme  in  the  hemolymph  of  insects  and  arthropods, 
which  explains  its  darkening  when  exposed  to  air.  This 
enzyme,  as  obtained  from  different  sources,  is  not  always  spe- 
cific for  tyrosin,  frequently  oxidizing  other  substances,  v.  Fiirth 
and  Schneider  found  the  product  of  oxidation  of  tyrosin  by 
animal  tyrosinase  related  to  certain  of  the  melanins  of  animal 
tissues,  and  believe  that  tyrosinase  is  responsible  for  the  pro- 
duction of  many  normal  pigments.  In  the  ink-sacs  of  the 
squid,  which  eject  an  inky  fluid  containing  melanin-like  pig- 
ment, tyrosinase  was  also  found,  corroborating  this  hypothesis. 
Florence  Durham 4  suggests  that  tyrosinase  in  the  skins  of  ani- 
mals is  responsible  for  their  pigmentation. 

Gonnermann 5  found  that  tyrosinase  from  beet-root  produced 
homogentisic  add  by  acting  on  tyrosin,  which  is  of  interest  in 
connection  with  the  congenital  hereditary  disease,  alkaptonuria 

1  Ergebnisse  der  PhysioL,  1902  (Bd.  I,  Abt.  1),  p.  213,  where  is  also  given 
a  resume  of  the  subject  of  intracellular  enzymes. 
'Pfliiger's  Arch.,  1898  (72),  105. 
3Hofmeister's  Beitr.,  1901  (1),  229, 

4  Proc.  Eoyal  Soc.,  1904  (74),  310. 

5  Pfliiger's  Arch.,  1900  (82),  289. 


80  ENZYMES 

(q.  v.),  in  which  the  urine  becomes  dark  upon  exposure  because 
of  the  presence  of  homogentisic  acid. 

Other  Oxidizing  Enzymes. — Of  the  great  number  of  other 
less  studied  oxidizing  enzymes  little  can  be  definitely  stated. 
Some  consider  that  they  are  largely  different  manifestations  of 
the  action  of  one  oxidizing  ferment,  but  against  this  view  Jacoby 
mentions  that  they  occur  distributed  unequally  in  different 
organs,  can  be  separated  from  each  other,  and  they  cause  dif- 
ferent reactions.  For  the  catalase  and  for  laccase  (which 
produces  the  Japanese  lacquer  by  an  oxidizing  process)  and 
perhaps  for  other  oxidizing  ferments,  iron  and  manganese  may 
be  essential  constituents.  Bertrand  l  considers  that  laccase  is 
an  organic  manganese  compound. 

Among  these  little  known  oxidizing  ferments  is  one  that 
seems  to  act  specifically  on  the  purin  bases,  changing  them  into 
uric  acid  (Spitzer2),  and  one  which  destroys  uric  acid,  in  the 
presence  of  catalase  (Croftan 3 ). 

Reducing"  enzymes  have  not  yet  been  satisfactorily 
demonstrated.  It  is  possible  that  they  do  not  exist,  and  that 
the  intracellular  reductions  that  are  carried  on  within  the  cells 
are  brought  about  by  simple  chemical  reactions  independent  of 
catalysis,  or  it  may  well  be  that  the  oxidizing  enzymes  in  some 
cases  act  reversibly ;  this  possibility  does  not  seem  to  have  been 
investigated. 

The  best  known  intracellular  reduction  is  that  of  methylene- 
blue,  which  can  be  readily  studied  experimentally  because  the 
blue  color  disappears  on  reduction  of  the  dye.  It  is  open  to 
question  if  this  particular  reduction  is  due  to  a  reducing  enzyme. 
According  to  Ricketts  4  the  reduction  depends  upon  two  bodies, 
one  thermostabile,  the  other  thermolabile,  recalling  the  reaction 
of  complement  and  amboceptor.  Johannsen  5  found  the  liver 
most  active  in  reducing  m  ethyl  en  e- blue,  the  kidney  next.  Ex- 
tracts of  the  organs  did  not  contain  the  reducing  substance, 
which  seems  to  be  bound  to  the  cell  elements. 

Oxidising  Enzymes  in  Pathological  Processes. — 
Although  the  oxidizing  enzymes  undoubtedly  play  an  important 
part  in  pathological  conditions,  they  have  been  but  little  investi- 
gated from  this  standpoint.  Jacoby  found  that  they  did  not 
disappear  from  the  degenerated  liver  in  phosphorus  poisoning 

1  Compt.  Rend.  Acad.  Sci.,  1897  (124),  1355. 
2Pfluger's  Arch.,  1899  (76),  192. 

3  Medical  Record,  1903  (54),  6. 

4  Jour,  of  Infectious  Diseases,  1904  (1),  590. 

5  Arb.  aus  d.  path.  Inst.  Tubingen,  1905,  vol.  5. 


THE  OXIDIZING  ENZYMES  81 

or  in  diabetes,  or  when  the  liver  undergoes  self-digestion,  which 
speaks  against  Spitzer's  contention  that  oxidase  is  a  nucleopro- 
teid.1  Schlesinger 2  found  that  it  is  less  in  amount  in  livers  of 
children  dead  from  gastro-intestinal  diseases  than  in  normal 
livers,  as  also  did  Briining.3  I  am  inclined  to  believe  that  fatty 
metamorphosis,  when  brought  about  by  poisons,  is  often  due  to 
inhibition  of  the  oxidizing  enzymes  (v.  fatty  metamorphosis). 
Buxton  4  failed  to  find  in  tumors  any  enzyme  giving  the  guaiac 
test  alone,  but  found  enzymes  that  did  so  in  the  presence  of 
H2O2  (peroxidases).  Catalase  was  present,  but  no  very  positive 
reactions  for  oxidizing  enzymes  were  obtained  by  the  indo-phenol 
reaction,  the  hydrochinon  reaction,  or  with  tyrosin  for  tyrosinase. 

Meyer 5  found  that  leucocytes,  whether  from  pus  or  leukemic 
or  pneumonic  blood,  contained  a  substance  oxidizing  guaiac 
directly,  without  the  presence  of  H2O2,  which  is  not  liberated 
until  the  cells  are  destroyed.  The  observation  of  Natalie 
Sieber6  that  oxidases  of  the  blood  and  of  vegetable  origin 
destroy  diphtheria  toxin  rapidly,  and  also  tetanus  toxin  and 
ricin,  has  been  confirmed  by  Loewenstein  as  far  as  destruction 
by  peroxide,  with  or  without  the  presence  of  catalase,  is  con- 
cerned. Oxidation  is  undoubtedly  an  important  process  in 
defending  the  body  against  other  forms  of  poisons.  (See  "  De- 
fense of  the  Body  against'  Poisons  of  Known  Composition.") 
Schmidt 7  has  found  that  by  oxidation  certain  poisonous  mor- 
phin  derivatives  are  rendered  non-poisonous  by  liver  extracts. 
Oxalic  acid  and  other  poisonous  fatty  acids  are  also  oxidized 
into  harmless  substances ;  phosphorus  and  sulphur  are  oxidized 
into  their  acids,  which  are  then  neutralized.  Indol  and  skatol 
are  oxidized  into  less  harmful  substances. 

Glycolytic  Enzymes.8 — The  oxidation  of  sugar  by  the 
tissues,  which  is  one  of  the  chief  sources  of  energy  in  the  ani- 
mal body,  presumably  takes  place  through  several  steps.  Of 
these,  it  is  believed  by  some  that  the  first  is  the  formation  of 
glycuronic  acid — 

//Q  //V> 

CH2OH  (CHOH)4C— H  +  O2     =     COOH-(CHOH)4C— H  +  H2O, 
(glucose)  (glycuronic  acid) 

1  Duccheschi  and  Almagia  (Arch.  ital.  Biol.,  1903  (39),  29)  also  found  the 
aldehydase  in  livers  of  phosphorus  poisoning  usually  no  less  abundant  than  in 
normal  livers. 

2  Hofmeister's  Beitr.,  1903  (4),  87. 

3  Monat.  f.'  Kinderheilk.,  1903  (2),  129. 

4  Jour.  Med.  Kesearch,  1903  (9),  356. 

5  Munch,  med.  Woch.,  1903  (50).  1489. 

6  Zeit.  physiol.  Chem.,  1901  (32),  573. 

7  Dissertation,  Heidelberg,  1901. 

8  Also  discussed  under  "  Diabetes,"  chap.  xxii. 


82  ENZYMES 

but  the  subsequent  changes  which  involve  decomposition  of  the 
straight  chain  are  not  at  present  understood.  Alcohol  and 
lactic  acid  are  possibly  steps  in  the  process.  Attempts  to  isolate 
from  various  organs  an  enzyme  oxidizing  glucose,  particularly 
from  the  pancreas,  muscle,  and  liver,  have  led  to  varying 
results  and  much  dissention,  but  it  is  probable,  because  of  these 
failures,  that  no  such  enzyme  exists  in  quantities  sufficient  to 
account  for  the  amount  of  sugar  combustion  that  is  normally 
accomplished.  O.  Cohnheim l  seems  to  have  explained  the 
failures  by  his  observation  that  the  pancreas  produces  a  sub- 
stance that  activates  an  inactive  glycolytic  enzyme  in  the  mus- 
cles, liver,  and  probably  in  other  organs.  More  or  less  of  this 
activating  substance  or  kinase  is  present  in  the  blood  and 
organs,  determining  a  certain  amount  of  activity  in  them  when 
they  are  removed  for  experiment,  and  explaining  the  varying 
and  inadequate  amount  of  glycolysis  often  observed. 

The  activating  substance  is  presumably  an  internal  secretion 
from  the  islands  of  Langerhans,  explaining  the  relation  of  these 
structures  to  diabetes.  Cohnheim  believes  that  the  activator 
unites  with  the  other  components  of  the  active  enzyme,  much 
as  complement  and  intermediary  body  unite  to  form  hemolytic 
and  bacteriolytic  substances.  Although  certain  features  of 
Cohnheim's  work  have  been  contested 2  the  most  essential 
features  seem  to  be  sufficiently  confirmed;  namely,  that  an  inter- 
action between  extracts  of  the  pancreas  and  extracts  of  muscle 
or  liver  produces  much  more  glycolysis  than  the  sum  of  their 
independent  action  would  be.3 

It  is  quite  possible  that  the  important  enzyme  in  glycolysis 
is  not  an  oxidizing  enzyme,  but  that  the  ordinary  oxidizing 
enzymes  of  the  cell  are  able  to  attack  the  sugar  only  after  it  has 
first  undergone  a  preliminary  splitting  by  the  specific  "  glyco- 
lytic" enzyme  (O.  Baumgarten 4 ). 

LIPASE 

In  all  cells  in  which  fat  is  found,  and  this  includes  practically 
all,  lipase  is  probably  present  in  greater  or  less  amount.  In 
the  discussion  of  the  reversible  action  of  enzymes  on  a  previous 
page  the  most  modern  conception  of  fat  metabolism  has  been 
explained,  which  considers  it  to  depend  upon  the  existence  of 

1  Zeit.  f.  physiol.  Chemie,  1903  (39),  336. 

2  Claus  and  Embden,  Hofmeister's  Beitr.,  1905  (6),  214. 

3  Simacek,  Cent.  f.  Physiol.,  1903  (17),  477,  and  others  have  claimed  priority, 
but  Cohnheim's  work  was  at  least  the  first  to  attract  general  notice. 

*  Zeit.  f.  exp.  Path.  u.  Ther.,  1905  (2),  53. 


LIPASE  83 

lipase  in  the  cells  and  fluids  throughout  the  body.  On  account 
of  the  technical  difficulties  in  the  way  of  using  the  higher  fats, 
such  as  triolein,  in  experimental  work,  the  esters  of  lower  fatty 
acids  have  generally  been  used,  particularly  ethyl  butyrate. 
Enzymes  splitting  ethyl  butyrate,  and  presumably  higher  fats, 
have  been  demonstrated  in  practically  all  tissues  examined ;  the 
names  of  Kastle  and  Loevenhart  in  this  country,  and  Hanriot 
in  France,  being  particularly  connected  with  this  work.  Whether 
in  all  cases  the  presence  of  this  reaction  is  proof  positive  of  the 
presence  of  an  enzyme  splitting  fats,  a  true  "  lipase,"  is  not  yet 
known ;  undoubtedly  as  a  rule  it  is,  but  there  have  been  many 
claims  made  that  true  lipase  does  not  exist  in  the  blood-serum. 
From  what  is  known  about  fat  metabolism  we  have  strong 
a  priori  grounds  for  believing  that  lipase  is  present  in  the  blood- 
serum  and  in  the  lymph,  and,  also,  we  have  some  experimental 
evidence.1 

Little  is  known  about  the  part  played  by  lipase  in  pathological 
conditions.  According  to  Achard  and  Clerc,2  the  amount  of  split- 
ting of  ethyl  butyrate  by  the  blood-serum  is  lessened  in  most  dis- 
eases, and  increases  and  decreases  with  the  health  of  the  patient. 
Clerc 3  found  that  acute  arsenic,  phosphorus,  and  diphtheria-toxin 
poisoning  increased  this  property  of  the  serum  while  chronic 
poisoning  and  staphylococcus  intoxication  lowered  it.  Poulain 4 
found  that  the  butyrate-splitting  power  of  lymph-glands  drain- 
ing infected  areas  was  decreased.  It  must  be  added  that  the 
value  of  these  observations  for  considering  pathological  condi- 
tions is  open  to  question.  The  same  may  be  said  of  the 
reported  finding  of  increased  butyrate-splitting  power  in  dia- 
betic blood  during  diabetes  with  lipemia ;  Fischer 5  observed,  on 
the  contrary,  in  a  case  of  extreme  lipemia  in  diabetes,  that  the 
lipolytic  power  of  the  blood  was  absent. 

Lipase  has  also  been  demonstrated  in  pus  by  a  number  of 
observers,6  who  agree  that  there  is  more  in  exudates  than  in 
transudates.  Zeri7  found  lipase  in  the  urine  only  when  pus  or 
blood  was  also  present. 

The  part  played  by  lipase  in  fatty  degeneration  must  be  of 
great  importance,  but  as  yet  it  has  been  little  considered,  except 

1  Full  references  to  the  literature  on  lipase  will  be  found  in  the  article  by 
Connstein  (Ergebnisse  der  Physiol.,  1904  (Bd.  3,  Abt.  1),194). 

2  Compt.  Kend.  Soc.  Biol.,  1902  (54),  1144. 

3  Compt.  Kend.  Soc.  Biol.,  1901  (53),  1131. 

4  Compt.  Eend.  Soc.  Biol.,  1901  (53),  786. 

5  Virchow's  Arch.,  1903  (172),  218. 

6  Achalme,  Compt.  Rend.  Soc.  Biol.,  1899  (51),  568 ;  Zeri,  II  Policlinic©,  1903 
(10),  433;  Memmi,  Clin.  Med.  Ital.,  1905  (44),  129. 

7  II  Policlinico,  1905  (12),  733. 


84  ENZYMES 

that  Duccheschi  and  Almagia l  found  no  appreciable  difference  in 
the  lipase  content  of  normal  and  phosphorus-poisoned  livers. 
This  question  will  be  considered  more  fully  in  discussing  fatty 
metamorphosis. 

Fat  necrosis  resulting  from  the  escape  of  pancreatic  juice  into 
the  peripancreatic  tissues  and  abdominal  cavity  undoubtedly  is 
largely  the  result  of  lipase  action.  Flexner2  found  lipase 
present  in  the  foci  of  necrosis,  and  Opie  demonstrated  the 
escape  of  lipase  into  the  urine  in  pancreatitis  with  fat  necrosis. 
Wells  (Joe.  tit.)  was  unable  to  produce  fat  necrosis  with  extracts 
of  liver  or  blood-serum  containing  lipase,  but  found  that  pan- 
creatic extracts  rich  in  lipase  produced  fat  necrosis,  while  the 
same  extracts  were  ineffective  after  the  lipase  had  been  destroyed 
by  the  trypsin.  (See  a  Fat  Necrosis,"  Chap,  xiii,  for  complete 
consideration.) 

1  Arch.  Ital.  Biol.,  1903  (39),  29. 
3  Jour.  Exper.  Med.,  1897  (2),  413. 


CHAPTER  III 
ENZYMES  (CONTINUED) 

Intracellular  Proteases1   (Proteolytic  Enzymes),  Including  a 
Consideration  of  Autolysis 

To  what  extent  synthesis  of  proteids  goes  on  in  the  body  is 
still  a  problem  ;  still  more  uncertain  is  the  part  played  by  rever- 
sible action  of  proteases.  If  the  possibility  of  resynthesis  of 
fats  by  lipase  is  still  unsettled,  the  possibility  of  resynthesis  of 
proteids  by  proteid-splitting  enzymes  must  be  still  more  open  to 
question.  There  is  evidence  enough  that  somewhere  in  the  body 
the  amino-acids  can  be  rebuilt  into  proteid,  for  Loewi,2  and 
since  him  several  others,  has  succeeded  in  keeping  animals  in 
nitrogenous  equilibrium  by  feeding  theui  products  of  proteol- 
ysis  that  contained  no  proteids  whatever,  and  as  the  proteids  of 
the  animal  body  are  incessantly  being  broken  down,  it  must  be 
that  they  were  replaced  by  synthesis  of  the  non-proteid  material 
fed  to  the  animals.  In  addition,  it  has  long  been  known  that 
amino-acids  absorbed  from  the  intestines  do  not  reappear  iu  the 
blood  coming  from  the  intestines,  indicating  that  they  are  resyn- 
thesized  into  proteids  while  passing  through  the  intestinal  wall. 
Cohnheim3  found  that  in  the  intestinal  epithelium  there  is  an  en- 
zyme, erepsin,  capable  of  splitting  album  oses  and  peptones  into  the 
amino-acids,  which  enzyme  presumably  exists  for  the  purpose  of 
securing  complete  cleavage  of  all  ingested  proteids  into  their  ulti- 
mate "  building  stones."  This  may  be  looked  upon  as  a  provision 
to  reduce  all  varieties  of  proteids  to  their  common  elements,  so 
that  the  body  by  quantitative  selection  can  resynthesize  them  into 
its  own  types  of  proteid,  for,  as  is  well  known,  foreign  proteids 
(e.  g.,  egg-albumin)  introduced  directly  into  the  blood  stream 
cannot  be  utilized,  but  are  excreted  unaltered  in  the  urine.  As 
was  shown  for  lipase,  the  assumption  that  such  synthesis  occurs 

1  As  long  as  the  possibility  still  exists  that  ferments  which  digest  proteids 
may  be  able  to  perform  a  certain  amount  of  synthesis  of  proteids,  the  term 
"  proteolytic  enzyme "  seems  to  be  less  suitable  than  the  term  "  protease," 
which  merely  means  an  enzyme  acting  on  proteids,  and  does  not  compel  us  to 
accept  any  particular  view  as  to  what  the  action  is. 

2Centr.  f.  PhysioL,  1902  (15),  590. 

3Zeitschr.  f.  physiol.  Chem.,1901  (33),  451 ;  1902  (35),  134. 


86  ENZYMES 

as  a  normal  physiological  process  by  reverse  enzyme  action, 
requires  that  the  proper  enzymes  be  present  in  the  cells  through- 
out the  body,  and  within  the  past  few  years  it  has  been  abund- 
antly demonstrated  that  such  is  the  case. 

For  over  half  a  century  it  has  been  known  that  amebse  digest 
solid  proteids  within  their  bodies,  but  it  is  only  within  a  few 
years  that  proteolytic  enzymes  have  been  definitely  isolated  from 
them.  It  has  been  much  the  same  with  the  intracellular  pro- 
teases of  the  higher  organisms.  In  1871  Hoppe-Seyler  referred 
to  the  liquefaction  of  dead  tissues  within  the  body  which  occurred 
without  putrefaction,  and,  as  he  noted,  resembled  the  effects  of 
the  digestive  ferments.  In  was  nearly  twenty  years  later  that 
Salkowski l  showed  definitely  that  this  softening  of  dead  tissues 
was  really  brought  about  through  a  true  digestion  by  intracel- 
lular enzymes,  which  produced  the  same  splitting  products  that 
were  at  that  time  considered  characteristic  for  tryptic  digestion 
(leucin  and  tyrosin).  The  process  he  named  "autodigestion."  This 
important  observation  remained  almost  unnoticed  for  ten  years 
more,  when  Jacoby,2  in  1900,  took  up  the  investigation  of  this 
matter  of  cellular  self-digestion,  and  after  this  the  importance  of 
the  principles  involved  became  for  the  first  time  generally  appre- 
ciated. Jacoby  rechristened  the  process  "  autolysis"  by  which 
name  it  is  now  commonly  known. 

AUTOLYSIS3 

Autolysis  is  generally  studied  by  the  method  used  by  Sal- 
kowski, which  depends  upon  the  difference  in  the  susceptibility 
of  bacteria  and  of  enzymes  to  antiseptics.  The  organs  are  ground 
up  to  a  pulp,  placed  in  flasks  with  or  without  the  addition  of 
water  or  dilute  acids,  and  bacterial  action  is  prevented  by  the 
addition  of  antiseptics  that  are  not  poisonous  to  enzymes — toluol 
and  chloroform  are  most  commonly  used.  It  is  possible  also  to 
secure  organs  in  an  aseptic  condition  and  to  permit  them  to 
undergo  autolysis  without  the  use  of  antiseptics,  but  the  practi- 
cal difficulties  are  such  that  this  method  is  seldom  used — it  is 
sometimes  designated  as  "  aseptic  autolysis"  in  contradistinction 
to  antiseptic  autolysis  by  the  Salkowski  method.  In  a  short  time 
it  can  be  seen  that  digestive  changes  have  taken  place,  particu- 
larly if  comparisons  are  made  with  control  flasks  in  which  the 

1  Zeit.  f.  klin.  Med.,  1890,  supplement  to  Ed.  17,  p.  77. 

2Zeit.  f.  physiol.  Chem.,  1900  (30),  149. 

3Kesum6  of  literature  by  Salkowski,  Deutsche  Klinik,  1903  (11),  147;  also 
see  Schlesinger,  Hofmeister's  Beitrage,  1903  (4),  87  ;  Oswald,  Biochem.  Centr., 
1905  (3),  365  ;  Levene,  Jour.  Amer.  Med.  Assoc.,  1906  (46),  776. 


AUTOLYSIS  87 

enzymes  have  been  destroyed  by  boiling.  To  determine  the 
rate  of  autolysis  the  amount  of  nitrogen  that  remains  in  the 
form  of  coagulable  compounds,  and  that  which  is  converted  into 
soluble,  non-coagulable  compounds  (albumoses,  peptones,  am- 
monia compounds,  amino-acids,  etc.),  is  compared.  The  method 
may  be  illustrated  by  a  concrete  example  :  A  given  specimen 
of  emulsionized  liver  tissue  was  permitted  to  digest  itself  for 
twenty-two  days.  At  the  end  of  that  time  39.4  per  cent,  of 
the  nitrogen  was  still  contained  in  the  compounds  that  remained 
insoluble  or  became  so  after  the  autolysis  was  stopped  by  boil- 
ing ;  while  60.6  per  cent,  of  the  nitrogen  was  in  a  soluble  form. 
A  control  specimen  from  the  same  liver  was  boiled  while  fresh 
to  kill  the  enzymes,  and  then  let  stand  under  the  same  condi- 
tions. In  this  specimen  90.4  per  cent,  of  the  nitrogen  was  in 
an  insoluble  form,  and  9.6  per  cent,  was  soluble.  Therefore, 
over  half  of  all  the  proteid  of  the  liver  had  been  changed  into  non- 
coagulable  substances  in  the  course  of  about  three  weeks  (at  37  °C.). 
Since  Jacoby's  paper  appeared,  the  field  has  been  invaded  by 
many  workers,  who  have  examined  practically  every  tissue  in 
the  body,  and  found  that  all  possess  the  power  of  self-digestion  ; 
or,  in  other  words,  proteases  are  present  in  every  cell  in  the  body. 
The  rate  of  digestion  is  very  different  in  different  organs,  how- 
ever, liver  digesting  rapidly  while  brain  and  muscle  tissue  digest 
much  more  slowly.  These  intracellular  proteases  are  not  alto- 
gether like  either  pepsin  or  trypsiu,  for  they  split  proteids  to 
its  simplest  elements,  whereas  pepsin  carries  the  digestion  only 
to  the  peptone  stage  (under  ordinary  conditions)  and  unlike 
trypsin  their  action  is  most  marked  in  a  faintly  acid  medium, 
and  is  entirely  checked  by  alkalies  no  stronger  than  0.4  per  cent. 
NaOH,  according  to  Wiener.1  Furthermore,  the  cleavage  prod- 
ucts seem  to  contain  a  much  larger  proportion  of  the  nitrogen 
in  the  form  of  ammonia  and  its  compounds  than  is  the  case  with 
tryptic  digestion.  It  is  quite  probable  that  in  autolysis  several 
intracellular  enzymes  are  in  action,  some  of  which  may  not  be 
present  in  pancreatic  or  gastric  juice.  On  the  whole,  however, 
the  products  are  quite  similar  to  those  obtained  by  tryptic  diges- 
tion. To  give  a  concrete  example,  Dakin 2  detected  in  the  prod- 
ucts of  autolysis  by  the  kidney  in  acid  solution,  the  following 
substances  :  Ammonia,  alanin,  a-aminovalerianic  acid,  leucin, 
a-pyrollidin  carboxylic  acid,  phenylalanin,  tyrosin,  lysin,  histidin, 
cystin,  hypoxanthin,  and  indol  derivatives,  including  probably 
tryptophan. 

1  Centr.  f.  PhysioL,  1905  (19),  349. 

2  Jour,  of  Physiology,  903  (30),  84. 


88  ENZYMES 

During  autolysis  the  changes  are  by  no  means  limited  to  the 
proteids.  Glycogen  is  split  into  glucose  very  early,  and  the 
sugar  undergoes  further  changes.  Fats  are  also  split  by  the 
lipase,  fatty  acids  being  found  in  autolyzed  organs.  Reducing 
substances  appear,  and,  as  before  mentioned,  numerous  volatile 
fatty  acids  are  produced.  The  increase  in  fat  described  by  some 
authors  is  probably  only  apparent,  and  due  rather  to  the  libera- 
tion of  the  fat  from  its  combination  with  the  proteids  so  that  it 
is  free  and  not  "  masked,"  as  in  normal  organs.  Lecithin  is 
also  decomposed,  yielding  cholin. 

The  nudeo-proteids  seem  to  be  attacked  by  the  autolytic  en- 
zymes, as  the  purin  bases  are  prominent  among  the  products  of 
autolysis,  and  in  quite  different  proportions  from  those  obtain- 
ing in  digestion  of  the  same  tissues  by  other  means.  Apparently 
autolytic  enzymes,  like  trypsin,  attack  the  proteid  group  of  the 
nucleoproteids,  liberating  the  nucleic  acids.  These  in  turn  are 
attacked  by  specific  enzymes,  nucleases^  which  liberate  the  purin 
bases,  which  are  further  decomposed  by  specific  enzymes, 
guanase,  adenase,  etc.2 

It  is  improbable  that  the  intracellular  enzymes  are  merely 
pancreatic  enzymes  taken  out  of  the  blood  by  the  cells,  because 
of  the  differences  previously  cited  ;  furthermore,  Matthes 3  found 
that  the  liver  retained  its  autolytic  power  after  the  pancreas 
had  been  extirpated  (in  dogs),  and  that  the  autolytic  degenera- 
tion of  cut  peripheral  nerves  went  on  just  the  same,  indicating 
that  the  autolytic  enzymes  do  not  owe  their  origin  to  the  pan- 
creas. 

RELATION  OF  AUTOLYSIS  TO  METABOLISM 

It  having  been  shown  that  proteases  are  present  in  all  cells, 
the  next  question  to  be  considered  is,  do  they  act  only  to  destroy 
tissues  after  death,  or  are  they  of  importance  in  metabolism  ? 
Since  it  is  presumably  necessary  for  proteids  to  be  split  into 
diffusible  and  easily  oxidized  forms  in  order  that  they  may  enter 
the  cell,  and  be  built  up  into  the  cell  proteids,  or  be  decomposed 
with  the  liberation  of  energy,  the  autolytic  proteases  may  be 
assumed  to  be  of  prime  importance  in  proteid  metabolism  ;  but 
to  prove  it  is  another  matter.  Jacoby  found  that  if  he  ligated 
off  a  portion  of  the  liver  and  let  it  remain  in  situ  in  the  animal 
the  necrotic  tissues  showed  an  accumulation  of  leucin,  tyrosin, 

1  Sachs,  Zeit.  physiol.  Chem.,  1905  (46),  337;  Jones,  Ibid.,  1903  (41),  101, 
and  1906  (48),  110. 

2  See  Schittenhelra,  Ibid.  (42),  251 ;  (43),  228;  (46),  354. 

3  Arch.  f.  exp.  Path.  u.  Pharm.,  1904  (51),  442. 


RELATION  OF  AUTOLYSIS  TO  METABOLISM          89 

and  other  splitting  products  of  the  proteids,  which  suggested 
that  these  same  bodies  are  being  formed  in  the  liver  constantly, 
but  that  they  are  as  constantly  removed  from  the  normal  organs 
by  the  circulating  blood,  or  are  undergoing  further  alterations 
which  cease  when  the  circulation  is  checked.  Among  other 
observations  possibly  bearing  on  the  same  question  are  those  of 
Hildebrandt,1  who  found  that  autolysis  in  the  functionating 
mammary  gland  is  much  more  active  than  in  the  resting  gland  ; 
and  of  Schlesinger, 2  who  found  that  autolysis  was  at  its  max- 
imum (in  rabbits)  in  new-born  animals,  decreasing  rapidly  in 
the  first  few  months  of  life,  and  that  in  conditions  associated 
with  emaciation  the  rate  of  autolysis  varied  directly  with  the 
degree  of  emaciation.  Wells3  sought  for  a  possible  influence 
on  autolysis  by  thyroid  extract,  which  increases  proteid  metab- 
olism, but  could  demonstrate  none  in  vitro.  Schryver,4  how- 
ever, found  that  autolysis  was  more  rapid  in  the  liver  of  dogs 
fed  thyroid  extract  for  some  days  before  death  than  it  was  in 
control  animals. 

The  possibility  of  synthesis  of  proteids  by  the  autolytic  en- 
zymes seems  not  to  have  been  investigated.  Proteid  synthesis 
seems  to  be  accomplished  on  a  large  scale  in  the  wall  of  the 
intestine,  and  the  enzyme  most  prominent  in  this  tissue  is  the 
erepsin  of  Cohnheim.  In  this  connection  the  statement  of 
Vernon 5  that  erepsiu  or  a  similar  enzyme  is  present  in  all  the 
tissues  of  the  body  may  be  of  some  significance.  Erepsin  is 
very  similar  to  the  autolytic  enzymes,  except  that  it  does  not 
attack  proteids  until  they  have  been  already  split  as  far  as 
proteoses,  and  the  products  of  its  action  are  not  quite  the  same 
(Cohnheim).  As  yet  the  exact  relation  of  erepsin  to  synthesis 
is  quite  unknown.  The  chief  positive  evidence  yet  obtained 
concerning  proteid  synthesis  by  proteases  is  the  "  plastein  reac- 
tion/7 i.  e.,  the  formation  of  an  insoluble  plastein  when  pro- 
teases are  added  to  proteose  solution  ;  this  occurs  not  only  with 
trypsin  and  pepsin,  but  also  with  extracts  of  organs  containing 
autolytic  proteases.6 

DEFENSE  OF  THE  CELLS  AGAINST  THEIR  AUTOLYTIC  ENZYMES 

The  question  of  why  the  autolytic  ferments  do  not  destroy 
the  cells  until  after  death  is  a  revival  of  the  old  problem  of 

1  Hofmeister's  Beitriige,  1904  (5),  463. 

2  Ibid,,  1903  (4),  87. 

3Araer.  Jour,  of  Physiol.,  1904  (11),  351. 
*  Jour,  of  Physiol.,  1905  (32),  159. 
5  Jour,  of  Physiol.,  1904  (32),  33. 
6Niirnberg,  Hofmeister's  Beitr.,  1903  (4),  543. 


90  ENZYMES 

".why  the  stomach  does  not  digest  itself/7  and  the  answer  that 
satisfies  some  is  that  dead  protoplasm  is  essentially  different 
from  living  protoplasm.  More  exact  replies  are  suggested  by 
Wiener's  studies  on  the  relation  of  the  reaction  of  the  tissues 
to  their  autolysis.  He  found  that  autolysis  does  not  begin  in 
an  organ  until  the  original  alkalinity  is  neutralized  by  the  acids 
which  are  formed  in  all  dead  and  dying  cells.1  If  enough  alkali 
is  added  to  the  material  from  time  to  time  to  neutralize  the 
acidity  as  it  develops,  autolysis  does  not  take  place.  Abundant 
amounts  of  organic  acids  are  formed  in  autolysis  of  the  tissues, 
principally  lactic,  acetic,  and  butyric  (Magnus-Levy),2  and  the 
latent  period  between  the  time  of  the  removal  of  an  organ  from 
the  body  and  the  appearance  of  autolysis  may  be  explained  by 
the  time  required  for  the  neutralization  of  alkalescence.  The 
old  observation  that  rigor  mortis  disappears  most  rapidly  in 
muscles  that  have  been  exhausted  just  before  death  is  also  prob- 
ably explained  by  the  greater  amount  of  acid  in  such  muscles.3 
If  we  imagine  that  autolysis  is  limited  to  periods  when  the  cells 
have  an  acid  reaction,  however,  we  limit  their  range  of  useful- 
ness in  the  living  cell  to  a  minimum,  since  during  life  the  tissue 
fluids,  and  presumably  the  cell  contents,  are  preponderatingly 
alkaline.  Perhaps  a  better  explanation  of  the  attack  of  the 
cells  by  their  own  enzymes  after  death  is  to  be  sought  in  the 
conditions  of  chemical  equilibrium.  During  life  constant  new 
supplies  of  proteid  are  being  brought  to  the  cell,  and  at  the 
same  time  the  products  of  proteolysis  are  presumably  being 
carried  away  by  the  circulation  or  being  changed  by  oxidative 
processes.  When  circulation  stops,  the  processes  of  splitting  go 
on  without  the  introduction  of  new  supplies  of  material,  and 
hence  the  tissues  are  not  replaced  as  fast  as  they  are  destroyed, 
and  the  products  of  their  decomposition  accumulate,  for  lack  of 
any  means  of  destroying  or  removing  them. 

Still  another  possible  defense  of  the  living  cells  may  be  found 
in  the  existence  of  specific  antienzymes.  Just  as  the  serum 
contains  antitrypsin,  so  it  seems  to  contain  substances  antag- 
onistic to  the  autolytic  enzymes.  Levene  and  Stookey 4  found 
that  tissue  juices  show  a  resistance  to  digestion,  and  Opie5 
found  that  the  serum  of  inflammatory  exudates  retarded  the 

1Opie  (loc.  cit.)  found,  however,  that  autolysis  of  leucocytes  was  more  rapid 
in  an  alkaline  medium. 

2  Hofmeister's  Beitr.,  1902  (2),  261. 

3Delrez  (Arch,  internat.  de  Physiol.,  1904  (1),  152)  found  by  cryoscopic 
methods  that  muscle  undergoes  rapid  autolysis  during  the  first  seven  to  nine 
hours  after  its  removal  from  the  body ;  after  this  the  rate  is  much  slower. 

4  Jour.  Med.  Kesearch.,  1903  (10),  217. 

5  Jour,  of  Exp.  Med.,  1905  (7),  316. 


DEFENSE  OF  CELLS  AGAINST  A  UTOLYTIC  ENZYMES    91 

action  of  the  autolytic  enzymes  that  were  contained  within  the 
leucocytes,  and  it  is  possible  that  continuance  of  the  circulation 
may  provide  antibodies  to  the  tissues  to  hold  the  intracellular 
enzymes  in  check,  possibly  without  interfering  with  their  action 
on  other  proteids  than  those  of  the  cell  structure. 

There  can  be  no  question  that  the  supply  of  food-stuff  is  of 
essential  importance  in  determining  autolytic  changes,  for  it 
has  been  found  by  Conradi,1  Rettger,2  and  Effront 3  that  bacteria 
and  yeasts  begin  to  undergo  autolysis  when  they  are  placed  in 
distilled  water  or  salt  solution,  which  they  do  not  do,  to  any 
such  extent  at  least,  when  in  nutrient  media.  (In  this  way 
it  has  been  found  possible  to  obtain  the  intracellular  toxins  of 
such  bacteria  as  typhoid  and  cholera.)  Autolysis  is  not  marked 
so  long  as  the  bacteria  are  supplied  with  nourishment,  but  when 
nutrient  material  is  lacking,  autolytic  decomposition  is  no  longer 
repaired  and  the  bacteria  disintegrate.  Presumably  the  changes 
are  the  same  in  living  cells,  and  anemic  necrosis  may  be 
explained  in  this  way.  Tissue  enzymes  are  also  capable  of 
digesting  bacteria  (Turro4). 

Another  direction  in  which  the  key  to  the  action  of  these 
enzymes  may  be  sought  has  been  indicated  by  Jacoby, 5  who 
found  that  to  a  certain  degree  the  autolytic  enzymes  of  each 
organ  are  specific  for  that  organ.  Liver  extract  will  not  split 
lung  tissue,  although  it  will  split  the  proteoses  that  are  formed 
in  lung  autolysis,  possibly  because  these  proteoses  are  less  specific 
than  the  proteids  from  which  they  arise,  or  perhaps  because  of  the 
erepsin  the  extract  contains  (Vernon).  Leucocytic  proteases, 
however,  seem  capable  of  splitting  foreign  proteids  of  all  sorts. 
Richet 6  states  that  the  protease  of  liver  tissue  does  not  attack 
either  muscle  tissue  or  liver  tissue  that  has  been  coagulated. 

Lastly,  it  must  be  considered  that  at  least  to  some  extent  the 
enzymes  exist  in  the  cells  in  their  inactive  zymogen  form,  which 
perhaps  are  changed  into  the  active  form  as  needed,  and  inhib- 
ited or  changed  back  again  when  their  work  is  temporarily 
finished.  A  rhythmical  change  of  this  nature  might  be  imagined 
as  occurring  and  accounting  for  interaction  by  the  enzymes, 
particularly  since  rhythmical  changes  in  metabolism  are  known 
to  occur  (e.  #.,)  rhythmical  production  of  carbon  dioxide  (Lyon 7 ). 

1  Deut.  med.  Woch.,  1903  (29),  26. 

2  Jour.  Med.  Kesearch,  1904  (13),  79. 
8  Bull.  Soc.  Chim.,  1905  (33),  847. 

4  Cent.  f.  Bakt,  1902  (32),  105. 

5  Hofmeister's  Beitr.,  1903  (3),  446. 

6  Compt.  Kend.  Soc.  Biol.,  1903  (55),  656. 

7  Science,  1904  (19),  350. 


92  ENZYMES 

AUTOLYSIS   IN   PATHOLOGICAL   PROCESSES 

All  absorption  of  dead  or  injured  tissues,  and  of  organic 
foreign  bodies,  seems  to  be  accomplished  by  means  of  digestion 
by  the  enzymes  of  the  cells  and  tissue  fluids.  We  may  distin- 
guish between  the  digestion  brought  about  by  the  enzymes  of 
the  digested  tissue  itself,  or  autolysis,  and  digestion  by  enzymes 
from  other  cells  or  tissue  fluids,  or  heterolysis  (Jacoby).  Heterol- 
ysis  is  accomplished  particularly  by  the  leucocytes,  which 
contain  ferments  capable  of  digesting  not  only  leucocytic  pro- 
teids  but  apparently  every  other  sort,1  from  serum-albumin  to 
catgut  ligatures.  The  heterolysis  may  be  intracellular  when 
the  material  to  be  digested  has  first  been  taken  up  by  the  cells 
(phagocytosis) ;  or  extra-cellular,  either  by  enzymes  normally 
contained  in  the  blood  plasma  and  tissue  fluids,  or  by  enzymes 
liberated  by  the  leucocytes  and  fixed  tissue  cells.  On  death 
and  dissolution  of  a  cell  the  intracellular  enzymes  are  released, 
but  it  is  not  known  to  what  extent  the  enzymes  may  be  secreted 
from  intact  living  cells.  As  far  as  pathological  processes  show, 
the  amount  of  liberation  of  enzymes  from  normal  cells  is  very 
slight,  if  any,  and  the  digestive  enzymes  of  the  blood  plasma 
seem  to  be  very  feeble,  but  this  is  perhaps  because  they  are 
largely  held  in  check  by  the  anti-enzymatic  substances  of  the 
serum.  Pathological  autolysis  and  heterolysis,  therefore,  are 
brought  about  chiefly  by  enzymes  liberated  from  dead  or  injured 
cells.  Bacteria,  however,  can  multiply  upon  a  medium  of  coagu- 
lated proteid,  which  suggests  that  they  also  secrete  proteolytic 
substances,  for  otherwise  it  would  be  difficult  to  explain  how 
they  secure  their  nourishment.  In  pathological  conditions, 
digestion  of  degenerated  tissues  seems  usually  to  be  the  result 
of  both  autolysis  and  heterolysis.  An  infarct  softens  because 
the  intracellular  enzymes  digest  the  dead  cells,  exactly  as  they 
do  when  the  tissue  is  removed  from  the  body,  ground  up,  and 
put  in  the  incubator  under  toluol.  In  addition  leucocytes 
wander  in,  disintegrate,  and  their  liberated  enzymes  help  in  the 
process,  as  also  do  to  a  less  degree  the  enzymes  of  the  blood 
plasma.  It  is  because  of  the  heterolysis  by  leucocytic  enzymes 
that  a  septic  infarct  becomes  softened  so  much  more  rapidly 

1  Many  authors  suggest  that  the  leucocytes  merely  carry  enzymes  from  one 
organ,  particularly  the  pancreas,  to  another,  and  that  these  enzymes  are  not 
formed  by  the  leucocyte  itself.  Opie  (Jour.  Exp.  Med.,  1905  (7),  759)  has 
shown,  however,  that  the  bone-marrow  contains  proteolytic  enzymes  which  are 
like  those  of  the  leucocytes  in  that  they  act  best  in  an  alkaline  medium, 
whereas  the  autolytic  enzymes  of  the  lymphatic  glands  and  most  other  tissues 
act  best  in  an  acid  medium.  This  leaves  little  room  for  doubt  that  the  leuco- 
cytes are  equipped  with  their  characteristic  enzymes  when  they  leave  the  bone- 
marrow,  and  that  they  are  not  obtained  later  in  the  pancreas  or  elswhere. 


AUTOLYSIS  IN  PATHOLOGICAL  PROCESSES  93 

than  does  a  sterile  infarct,  and  by  comparing  the  rate  of  soften- 
ing in  septic  and  aseptic  iufarcts  we  see  that  the  cellular  autol- 
ysis is  a  very  slow  process  as  compared  to  the  heterolysis 
accomplished  by  the  leucocytes.  The  explanation  of  this  may 
lie  in  the  fact  that  most  intracellular  proteases  act  best  in  an  acid 
medium  (Wiener), while  leucocytic  proteases  act  best  in  an  alkaline 
medium  (Opie),  and  the  infarcts  of  small  size  are  seeped  through 
by  alkaline  blood  fluids.  When  an  infarct  is  large,  we  find  it 
undergoing  central  softening  while  the  periphery  remains  firm  ; 
this  corroborates  our  hypothesis,  for  acids  are  developed  during 
autolysis  (Magnus-Levy),  which  at  the  periphery  are  neutralized 
by  the  blood  plasma,  so  that  only  at  the  center  is  autolysis 
active.  The  inhibiting  action  of  the  serum  also  has  a  similar 
effect,  limiting  autolysis  at  the  periphery. 

In  the  case  of  septic  softening  the  action  of  the  bacteria 
needs  also  to  be  taken  into  consideration,  since  they  also  pro- 
duce proteolytic  ferments,  but  their  effect  seems  to  be  relatively 
small  as  compared  with  leucocytic  digestion.  Intracellular 
digestion  of  necrotic  tissue  by  leucocytes  seems  also  to  be  rela- 
tively unimportant.  Suppuration,  therefore,  must  be  considered 
as  the  result  of  digestion  of  dead  tissue  by  enzymes  derived 
from  the  leucocytes,  the  plasma,  the  bacteria,  and  the  destroyed 
cells  themselves.  A  tubercle  does  not  ordinarily  suppurate, 
because  the  tubercle  bacillus  and  the  substances  it  produces  are 
not  strongly  chemotactic,  and  hence  not  enough  leucocytes  enter 
the  necrotic  area  to  produce  a  digestive  softening.  The  enzymes 
of  staphylococcus  are  much  more  strongly  proteolytic  than 
those  of  streptococcus  (Knapp l  ),  which  may  be  one  reason 
why  the  latter  so  much  more  frequently  produces  lesions  with- 
out suppuration  than  does  the  former.  Necrotic  areas  of  any 
kind  are  absorbed  by  similar  processes.  Autolysis  of  tumors 
is  quite  active  in  specimens  removed  from  the  body,  and  the 
areas  of  necrosis  that  occur  commonly  in  tumors  are  absorbed 
in  this  way.  Apparently  all  varieties  of  cells  are  subject  to 
autolysis  or  heterolysis  whenever  they  are  killed  or  sufficiently 
injured.  Atrophy  may  be  looked  upon  as  an  autolysis  in  the 
normal  course  of  catabolism,  not  met  by  a  corresponding  build- 
ing up  of  the  proteids. 

The  products  of  autolysis  may  of  themselves  be  toxic ;  albu- 
moses  and  peptones  certainly  are,  and  the  other  cleavage  products 
are  probably  not  altogether  innocuous.  (See  "Autointoxication. ") 
Some  of  the  symptoms  of  suppuration,  particularly  the  fever 
and  chills,  have  been  ascribed  to  the  autolytic  products  rather 

1  Zeit.  f.  Heilk.  (Chir.),  1902  (23),  236. 


94  ENZYMES 

than  to  the  bacterial  poisons,  particularly  as  aseptic  suppuration 
is  accompanied  by  fever.  Degenerative  changes  in  nervous  tis- 
sue are  associated  with  autolytic  decomposition  of  the  lecithin 
(Noll *  )  and  the  liberated  cholin,  or  its  more  toxic  derivatives, 
may  be  a  source  of  intoxication.2  In  all  conditions  associated 
with  autolysis,  such  as  resolving  pneumonic  exudates,  large 
abscesses,  softening  tumors,  etc.,  albumoses  (and  peptones?) 
may  appear  in  the  urine.  Autolytic  products  may  also  be 
hemolytic  (Levaditi3),  and  they  may  prevent  clotting  of  the 
blood  (Conradi 4 ). 

Work  has  been  reported  upon  autolytic  processes  in  a  number 
of  pathological  conditions,  which  may  be  discussed  briefly  as 
follows : 

Extldates. — The  presence  of  leucin,  tyrosin,  proteoses,  and 
peptones  in  pus  has  been  known  for  many  years,  and  the  reason 
for  their  appearance  is  now  clear.  Miiller, 5  many  years  ago, 
observed  that  purulent  sputum  digested  fibrin,  but  that  non- 
purulent  sputum  did  not  have  this  property.  Achalme 6  found 
that  pus  would  dissolve  gelatine,  fibrin,  and  egg-albumen.  As- 
coli  and  Mareschi 7  detected  autolysis  in  sterile  exudates  obtained 
experimentally.  Umber8  found  that  ascitic  fluid  exhibited 
autolytic  changes,  which  observation  could  not  be  confirmed  by 
Schiitz 9  in  pleural  exudates  and  ascitic  fluids.  Zak 10  found  that 
autolysis  was  inconstant  in  various  exudates.  The  differences 
in  these  results  are  probably  explained  by  Opie's  n  observation 
that  in  experimental  inflammatory  exudates  the  leucocytes  are 
capable  of  marked  autolysis,  whereas  the  serum  contains  an 
antibody  which  holds  this  autolysis  in  check  ;  if  the  antibody 
is  destroyed  by  heat,  then  the  serum  proteids  are  also  digested 
by  the  leucocytic  enzymes.  This  antibody  seems  to  be  contained 
normally  in  the  blood-serum.  In  old  exudates  the  antibodies 
are  decreased,  and  autolysis  then  occurs,  explaining  the  variable 
results  of  Umber,  Schiitz  and  Zak.  The  intracellular  proteases 
of  the  poly  nuclear  leucocytes  act  best  in  an  alkaline  medium  -r 
those  of  the  mononuclears  in  an  acid  medium.  Exudates  pro- 


1  Zeit.  physiol.  Chemie,  1899  (27),  380. 

2  See  Halliburton,  Ergebnisse  der  Physiol.,  1904  (4),  24. 

3  Ann.  d.  1'  Tnst.  Pasteur,  1903  (17),  187. 

4  Hofmeister's  Beitr.,  1901  (1),  136. 
5Kossel,  Zeit  f.  klin.  Med.,  1888  (13),  149. 
6Compt.  Kend.  Soc.  Biol.,  1899  (51),  568. 

7  See  Mal/s  Jahresbericht,  1902  (32),  568. 

8  Munch,  med.  Woch.,  1902  (49),  1169. 

9  Cent.  f.  inn.  Med.,  1902  (23),  1161. 
10Wien.  klin.  Woch.,  1905  (18),  376. 

11  Jour,  of  Exper.  Med.,  1905  (7),  316  and  759  ;  1906  (8),  410. 


AUTOLYSIS  IN  PATHOLOGICAL  PROCESSES  95 

duced  by  bacterial  infection  also  seem  to  possess  the  properties 
above  described.  Galdi1  found  autolysis  greater  in  exudates 
than  in  transudates,  but  observed  no  constant  relation  between 
the  number  of  leucocytes,  or  the  amount  of  chlorides,  and  the 
rate  of  autolysis. 

Knapp  2  holds  that  in  pus  the  cocci  and  the  enzymes  they 
produce  are  responsible  for  much  of  the  digestion.  Pus  cells 
alone  do  not  undergo  digestion  so  rapidly  as  when  bacteria  are 
present,  and  digestion  is  more  rapid  if  the  bacteria  are  alive 
than  when  inhibited  or  killed  by  antiseptics.  Streptococcus  is 
almost  inactive,  staphylococcus  is  quite  active,  and  B.  coli  still 
more  so.  He  could  find  no  relation  between  the  autolytic 
power  of  the  pus  and  the  severity  of  the  infection  from  which 
it  resulted.  (See  also  the  discussion  of  the  "  Chemistry  of  Pus,  " 
Chap,  x.) 

Pneumonia.  —  In  the  stage  of  resolution  lobar  pneumonia 
presents  a  striking  example  of  autolysis.  The  often-remarked 
phenomenon  that  the  lung  tissue  itself  is  not  in  the  least  affected, 
while  the  dense  contents  of  the  alveoli  are  rapidly  dissolved  and 
removed  is  explained  by  the  invariable  immunity  of  living 
cells  to  digestive  enzymes.  Except  for  some  slight  possible 
assistance  by  the  alveolar  epithelium  and  the  enzymes  of  the 
serum,  the  enormous  and  rapid  digestion  of  pneumonic  exudates 
is  accomplished  by  the  leucocytic  enzymes.  The  rapid  rate  of 
digestion  may  be  accounted  for  by  the  absence  of  circulation 
within  the  alveolar  contents,  which  permits  the  leucocytes  to 
act  unimpeded  by  the  anti-bodies  of  the  blood  plasma.  Diges- 
tion of  the  exudate  continues  after  death,  accounting  for  the 
marked  diffuse  softening  observed  in  pneumonic  lungs  in  bodies 
kept  some  days  before  autopsy.  As  long  ago  as  1888,  Kossel  3 
mentioned  that  Fr.  Miiller  had  found  that  glycerin  extracts  of 
purulent  sputum  exhibited  a  digestive  action  upon  fibrin  and 
coagulated  proteid,  whereas  non-purulent  sputum  did  not  possess 
this  property.  In  1877  Filehne  extracted  ferments  in  the  same 
way  from  the  sputum  in  gangrene  of  the  lung  ;  Stolniknow  in 
1878,  found  a  similar  ferment  in  pneumonic  sputa,  and  Esche- 
rich  in  1885  showed  that  the  proteolytic  action  of  tuberculous 
sputum  was  independent  of  putrefaction.  Other  early  observa- 
tions of  similar  nature  are  reviewed  by  Simon,4  who  demonstrated 
the  presence  of  leucin  and  tyrosin  in  the  autolyzed  lungs.  In 
a  later  work  Miiller  reports  finding  three  grams  of  leucin  and 


Folia  Hemat,  1905  (2),  529. 

2  Zeitschr.  f.  Heilk.,  1902  (23,  Chir.  Abt),  236. 

3  Zeit.  f.  klin.  Med.,  1888  (13),  149. 
4Deut.  Arch.  klin.  Med.,  1901  (70),  604. 


96  ENZYMES 

tyrosin  in  a  pneumonic  lung,  as  well  as  lysin,  histidin,  and 
purin  bases  from  the  decomposed  nucleoproteids.  Flexner  l 
noted  that  autolysis,  while  very  rapid  in  the  gray  stage,  is  but 
slight  in  the  red  stage  (because  of  paucity  of  leucocytes)  and 
also  in  unresolved  pneumonia,  which  he  considers  as  due  to 
some  interference  with  autolysis.  Silvestrini2  found  that  in 
gray  hepatization  the  reaction  was  strongly  acid,  in  red  faintly 
so  ;  the  gray  hepatization  showed  more  peptone,  and  leucin  and 
lactic  acid  were  both  demonstrable.  A  fibrin-digesting  enzyme 
was  isolated,  and  milk  was  coagulated.  Rzentkowski 3  found 
an  increase  of  non-coagulable  nitrogen  in  the  blood  of  pneu- 
monics,  probably  resulting  from  autolysis  in  the  exudate.4 

Necrotic  Areas. — Jacoby  5  found  that  if  a  portion  of  a 
dog's  liver  was  ligated  off  and  the  animal  kept  alive  for  some 
time  the  necrotic  tissue  contained  the  same  products  that  he  had 
obtained  in  experimental  autolysis.  The  absorption  of  necrotic 
tissues  generally  is  ascribable  to  either  autolysis  or  heterolysis. 
Presumably  there  is  no  great  difference  in  the  self-digestion  of 
an  organ  which  is  necrotic  because  its  blood  supply  is  cut  off 
and  of  a  similar  organ  removed  from  the  body  aseptically  and 
allowed  to  undergo  aseptic  autolysis  in  an  incubator.  At  the 
periphery  there  might  be  some  effects  produced  by  the  inhibi- 
tive  action  of  the  serum  or  the  digestive  action  of  the  leuco- 
cytes, but  beyond  that  no  marked  differences  are  to  be  expected. 

A  study  of  the  relation  of  autolysis  to  the  histological 
changes  that  occur  in  necrotic  areas  by  Wells 6  gave  evidence 
that  there  occurs  early  a  decomposition  of  the  nucleoproteids  of 
the  nuclei,  which  is  probably  brought  about  by  the  intracellular 
autolytic  enzymes.  The  liberation  of  the  nucleic  acid  and  the 
reduction  in  the  bulk  of  nuclear  material  through  the  digestion 
away  of  the  proteid  is  probably  the  cause  of  the  pycnosis 
observed  in  necrotic  areas.  Later  the  nucleic  acids  are  further 
decomposed  through  the  special  enzymes  described  by  Jones, 
Sachs,  and  others  the  "  nucleases."  This  is  presumably  the 
cause  of  the  loss  of  nuclear  staining  so  characteristic  of  necrosis. 
That  these  changes  are  due  to  the  intracellular  enzymes  was 
shown  by  implanting  in  animals  pieces  of  sterile  tissues,  the 
enzymes  of  which  had  been  destroyed  by  heating;  these 

lUniv.  of  Penn.  Med.  Bull.,  1903  (16),  185. 

2  Bull,  del  Soc.  Eustachiana,  1903,  abst.  in  Biochem.  CentralbL,  1903  (1), 
713. 

3  Virchow's  Arch.,  1905  (179),  405. 

4Kietschel  and  Langstein  (Biochem.  Zeitschr.,  1906  (1),  75),  report  the 
isolation  of  considerable  quantities  of  leucin  from  the  urine  of  a  pneumonic. 
5Zeit.  physiol.  Chem.,  1900  (30),  149. 
6  Jour.  Med.  Research,  1906  (15),  149. 


AUTOLYSIS  IN  PATHOLOGICAL  PROCESSES  97 

were  found  to  undergo  alterations  only  after  several  weeks, 
and  then  as  the  result  of  the  action  upon  them  of  invad- 
ing leucocytes.  The  slow  rate  of  autolysis  that  occurs  in 
infarcts  and  other  aseptic  areas  is  presumably  due  to  the  action 
of  the  antibodies  of  the  serum,  for  it  was  found,  experimentally, 
that  the  histological  changes  of  autolysis  when  the  tissues  are 
placed  in  heated  serum  proceed  about  twice  as  rapidly  as  when 
they  are  placed  in  fresh  serum,  Chemotactic  substances  do 
not  seem  to  be  formed  in  aseptic  dead  tissues,  but  the  slow 
absorption  of  such  tissues  is,  however,  finally  accomplished  by 
the  leucocytes  acting  from  the  periphery,  there  being  little 
actual  autolysis  of  the  dead  cells  by  their  own  enzymes.  The 
rapidity  with  which  autolytic  changes  occur  in  different  organs, 
as  indicated  by  the  disappearance  of  nuclear  staining,  seems  to 
be  about  as  follows :  (1)  Liver,  kidney  (epithelium  of  convo- 
luted tubules) ;  (2)  spleen,  pancreas ;  (3)  kidney  (collecting 
tubules,  straight  tubules,  glomerules) ;  (4)  lung  (alveolar  and 
bronchial  epithelium)  ;  (5)  thyroid  ;  (6)  myocardium  ;  (7)  vol- 
untary muscle ;  (8)  skin  (epithelium) ;  (9)  brain  (cortical  cells). 
Stroma  cells  seem  to  be  attacked  chiefly  by  enzymes  from  the 
parenchyma  cells.  Of  all  cellular  elements,  the  endothelium  of 
the  vessels  seems  to  have  the  greatest  resistance  to  both  autol- 
ysis and  heterolysis. 

Degenerated  nervous  tissue  also  undergoes  a  slow  autolysis 
which,  according  to  Noll,1  results  in  the  splitting  of  protagon 
with  liberation  of  lecithin.  Mott,  Halliburton,2  Donath,  and 
others  have  shown  that  in  nerve  destruction  lecithin  is  split  up 
with  liberation  of  cholin  (see  "  Cholin  "  ).  Koch  and  Goodson  3 
found  that  degenerated  nervous  tissue  is  characterized,  chemi- 
cally, by  containing  a  relatively  increased  amount  of  nucleo- 
proteids,  with  an  absolute  decrease  in  solid  constituents,  while 
the  lecithans  are  greatly  altered. 

In  caseation  autolysis  is  very  slight,  as  is  shown  by  the  per- 
sistence of  the  caseous  material  for  long  periods  of  time  without 
absorption.  Presumably  the  toxin  of  tuberculosis  destroys  the 
autolytic  ferments  of  the  cells  it  kills,  and  as  there  is  little 
chemotactic  influence,  leucocytes  do  not  enter  the  caseous  area. 
Spiethoff4  found  that  pure  caseous  material  is  usually  free  from 
even  traces  of  albumose  and  peptone,  but  the  caseous  material 
at  the  periphery  mixed  with  tissue  elements  contains  them  in 
very  small  quantities,  suggesting  that  at  the  periphery  of 

1  Zeit.  physiol.  Chem.,  1899  (27),  390. 

2  General  resume*  in  Ergebnisse  der  Physiol.,  1904  (4),  24. 
8  Amer.  Jour.  Physiol.,  1906  (15),  272. 

4  Cent.  f.  inn.  Med.,  1904  (25),  481. 


98  ENZYMES 

caseous  areas  some  slight  autolysis  does  occur.  The  fact  that 
£.  tuberculosis  is,  itself,  very  poor  in  proteolytic  enzymes  as 
compared  with  most  other  bacteria  may  be  another  factor. 
When  leucocytes  are  attracted  into  a  tuberculous  focus  then 
softening  goes  on  rapidly,  showing  that  there  is  no  loss  of 
digestibility  of  the  caseous  material,  but  merely  a  lack  of 
enzymes.  Pus  from  a  cold  tuberculous  abscess  will  not  digest 
fibrin,  but  if  iodoform  is  injected,  leucocytes  enter  in  great  num- 
bers, softening  is  rapid,  and  the  pus  will  then  digest  fibrin 
(Heile1). 

I/iver  Degenerations. — The  relation  of  the  disintegration 
observed  in  phosphorus-poisoning  and  acute  yellow  atrophy  to 
the  experimental  autolysis  of  the  liver  has  been  the  object  of 
much  study.  Salkowski  originally  pointed  out  that  the  same 
products  were  found  in  the  blood,  urine,  and  liver  tissue  in  acute 
yellow  atrophy  as  are  produced  in  autolysis.  Jacoby  2  found 
that  the  livers  of  dogs,  taken  just  as  the  animals  were  dying  of 
phosphorus-poisoning,  contained  free  leucin  and  tyrosin ;  also, 
he  found  that  the  rate  of  autolysis  of  such  livers  after  removal 
from  the  body  was  much  greater  than  in  normal  livers.  The 
oxidizing  ferments  (aldehydase)  are  not  destroyed  by  the  pro- 
cess. He  found  that  addition  of  minute  amounts  of  phosphorus 
to  liver  enzymes  did  not  increase  their  proteolytic  power; 
nevertheless,  he  seems  inclined  to  assume  that  in  phosphorus- 
poisoning  alteration  in  the  autolytic  enzymes  is  an  important 
factor  in  the  liver  degeneration.  It  would  seem  much  more 
probable  that  phosphorus  is  a  poison  that  kills  cells  and  does 
not  destroy  their  autolytic  enzymes,  hence  favoring  autolysis. 
The  liver  degeneration  following  chloroform  poisoning  may, 
perhaps,  be  explained  in  a  similar  way,  the  cells  behaving 
exactly  as  bacteria  would  do  under  the  same  conditions.  Tay- 
lor 3  has  analyzed  several  livers  in  degenerative  conditions  for 
amino-acids  and  found  them  only  in  one  liver,  which  showed 
necrosis  probably  due  to  chloroform  poisoning,  and  which  was 
from  a  case  clinically  resembling  acute  yellow  atrophy.  Here 
he  obtained  4  gm.  of  leucin,  2.2  gm.  of  tyrosin,  and  2.3  gm.  of 
arginin  nitrate.  Waldvogel  and  Tintemann,4  in  phosphorus 
livers,  found  an  increase  in  protagon,  jecorin,  fatty  acids,  cho- 
lesterin,  and  neutral  fat,  while  lecithin  was  decreased.  Wake- 
man  5  found  arginin,  histidin,  and  lysin  decreased  in  phospho- 

1  Zeit.  klin.  Med.,  1904  (55),  508. 
2Zeit.  f.  physiol.  Chem.,  1900  (30),  174. 

3  Univ.  of  Calif.  Public,  (pathol.),  1904  (1),  43. 

4  Cent.  f.  Path.,  1904  (15),  97. 
5Berl.  klin.  Woch.,  1904  (41),  1067. 


AUTOLYSIS  IN  PATHOLOGICAL  PROCESSES  99 

rus  livers  in  proportion  to  the  total  nitrogen,  indicating  that 
the  proteid-splitting  enzyme  in  this  condition  either  picks  out 
certain  varieties  of  proteids  first,  or  removes  the  nitrogen-rich 
constituents  most  rapidly. 

It  is  probable  that  many  poisons  may  destroy  the  liver  cells 
to  such  an  extent  that  they  cannot  maintain  their  normal  chem- 
ical equilibrium,  without,  at  the  same  time,  destroying  the 
autolytic  enzymes.  When  this  occurs,  the  liver  undergoes 
autolysis,  and  we  get  marked  degenerative  changes  with  appear- 
ance of  amino-acids  in  the  blood  and  urine,  reduction  in  coagu- 
lability of  the  blood  and  numerous  hemorrhages,  giving  a  picture 
both  clinically  and  anatomically  more  or  less  like  that  of  typical 
acute  yellow  atrophy.  Chloroform  is  a  poison  that  stops  cell 
activities  without  destroying  the  proteolytic  enzymes,  hence  the 
cells  undergo  autolysis,  and,  as  a  result,  we  have  many  cases  of 
what  appears  to  be  acute  yellow  atrophy  following  chloroform 
anesthesia.  (See  "  Acute  Yellow  Atrophy,"  Chap,  xviii.)  Prob- 
ably the  liver  changes  in  puerperal  eclampsia,  and  in  strepto- 
coccus and  other  septicemias  are  of  a  similar  nature.1 

Postmortem  changes  are  undoubtedly  due  to  two  fac- 
tors, bacterial  action  and  autolysis.  In  tissues  kept  at  a  low 
enough  temperature  to  exclude  bacterial  action,  but  not  so  low 
as  to  absolutely  stop  enzyme  action,  there  occurs  a  slow  autol- 
ysis ;  this  constitutes  the  "  ripening "  process  of  meat.  Fish 
flesh  may  also  ripen  when  made  sterile  in  saturated  salt  solutions, 
as  Schmidt-Nielsen2  has  shown  occurs  with  salted  herrings, 
oxy-acids  and  xanthin  bases  being  prominent  among  the  prod- 
ucts. The  softening  of  muscles  in  rigor  mortis  is  probably  also 
an  autolytic  manifestation,  as  muscles  contain  proteases  acting 
best  in  acid  medium,  and  the  muscle  is  known  to  become  increas- 
ingly acid  after  circulation  ceases  within  it.  The  short  duration 
of  rigor  mortis  when  the  body  is  kept  warm,  and  its  early  dis- 
appearance when  death  has  been  preceded  by  muscular  exhaus- 
tion (which  increases  the  acidity),  agree  with  this  view.  The 
early  postmortem  softening  of  many  organs  in  pathological 
conditions  is  also  probably  an  autolytic  manifestation.  Flexner  3 
has  called  attention  to  this  in  relation  to  the  softening  of  the 
parenchymatous  organs  in  acute  infectious  diseases,  such  as 
typhoid  and  septicemia.  Schumm 4  noted  great  autolytic  activ- 
ity in  a  swollen  spleen  from  a  case  of  perityphlitis. 

Histological  changes  are  produced  by  autolysis  in  the  organs 

1  Wells,  Jour.  Amer.  Med.  Assoc.,  1906  (46).  341. 

2  Hofmeister's  Beitrage,  1903  (3),  267. 

3  Loc.  cit.  4  Loc.  cit.,  infra. 


100  ENZYMES 

after  death  that  are,  as  might  be  expected,  much  like  those  seen 
in  necrotic  areas.1  At  first  the  changes  resemble  those  of  par- 
enchymatous  degeneration  (cloudy  swelling),  and  often  there  is 
an  apparent  increase  in  fat,  which  is  probably  due  to  liberation 
of  masked  fat  through  the  destruction  of  the  proteid.2  Nuclear 
staining  is  lost  (karyolysis),  and  eventually  even  cell  forms 
become  indistinguishable,  but  this  does  not  ordinarily  become 
complete  in  autolysis  without  bacterial  complication. 

Still-born  children  that  have  been  carried  for  some  time 
after  death  usually  show  considerable  disintegration  of  the  vis- 
cera, especially  the  liver.  This  is  undoubtedly  due  to  autolysis, 
which  Schlesinger3  has  shown  can  begin  before  birth  if  the 
fetus  dies  in  utero. 

Autolysis  in  Relation  to  Infection. — According  to  Con- 
radi4  the  substances  produced  in  tissue  autolysis  have  a  decided 
inhibiting  effect  upon  bacteria,  which  apparently  depends  upon 
the  antiseptic  properties  of  the  aromatic  derivatives  that  are 
split  out  of  the  proteid  molecule  in  autolysis.  This  action  is 
manifested  not  only  in  vitro,  but  the  autolytic  products  will  also 
render  harmless  lethal  doses  of  certain  bacteria  if  they  are  in- 
jected simultaneously  with  the  bacteria  into  an  animal.  It  may 
well  be  questioned,  however,  whether  enough  of  these  substances 
ever  accumulates  in  infected  tissues  during  intra  vitam  autolysis 
to  have  much  effect  upon  the  infecting  bacteria ;  yet  this  prop- 
erty may  possibly  explain  the  sterilization  of  old  pus  collections 
and  similar  infected  accumulations  within  the  body.  The  bac- 
teria themselves  also  produce  autolytic  products  that  are  power- 
fully bactericidal.  (See  "  Bacteria,"  Chap.  iv). 

Blum 5  found  that  the  autolytic  products  of  lymph-glands 
neutralized  tetanus  toxin,  but  were  inactive  against  diphtheria 
toxin  and  cobra  venom.  Products  from  other  autolyzed  organs 
and  from  fresh  lymph-glands  were  without  influence  on  the 
tetanus  toxin.  The  antitoxic  principles  of  the  autolytic  product 
were  destroyed  by  heating,  weakened  by  acids  and  alkalies,  and 
in  other  respects  showed  properties  strikingly  like  those  of  true 
antitoxin.  It  is  quite  possible  that  bacterial  toxins  may  be 
destroyed  by  autolytic  enzymes,  for  Baldwin  and  Levene 6  have 
shown  that  trypsin,  pepsin,  and  papain  destroy  tetanus  and  diph- 

1  More  fully  discussed  by  Wells,  Jour.  Med.  Research.  1906  (15),  149. 

2Siegert  ( Hofmeister's  Beitr.,  1901  (1),  114)  found  no  actual  increase  in  fats 
and  fatty  acids  in  autolysis  even  when  an  increase  was  apparent  histologically, 
although  ether-soluble  materials  of  other  nature  than  fat  may  be  increased. 

3  Hofmeister's  Beitr.,  1903  (4),  87. 

4  Hofmeister's  Beitr.,  1901  (1),  193. 
5 Hofmeister's  Beitr.,  1904  (5),  142. 

6  Jour.  Med.  Research,  1901  (6),  120. 


AUTOLYSIS  IN  PATHOLOGICAL  PROCESSES          101 

tberia  toxin,  while  tuberculin  is  destroyed  by  trypsin,  but  not 
readily  by  pepsin,  possibly  because  it  is  of  a  nucleoproteid 
nature. 

On  the  other  hand,  there  are  many  pathogenic  bacteria  which 
do  not  secrete  their  toxic  materials,  but  store  them  up  within  the 
cell  body,  e.  g.,  typhoid,  cholera,  and,  indeed,  the  majority  of 
pathogenic  forms.  These  endotoxins  are  probably  liberated  from 
the  bacteria  only  through  digestion  of  their  cells,  either  by  their 
own  autolytic  enzymes,*  or  by  the  enzymes  of  the  infected  tissues 
and  leucocytes. 

I/eukemia. — The  abundant  elimination  of  uric  acid  and 
other  purin  bodies  in  the  urine  in  leukemia  testifies  to  the  great 
amount  of  destruction  of  nucleoproteid  that  is  going  on  during 
the  disease,  and  this  is  probably  derived  from  the  autolysis  of 
leucocytes.  Schumm1  has  studied  the  autolytic  changes  in  a 
spleen  from  a  case  of  acute  leukemia  (variety  not  stated)  with 
the  following  results :  The  leukemic  spleen  immediately  after 
death  contains  much  proteose,  and  this  soon  disappears,  while 
leucin,  tyrosin,  lysin,  and  ammonia  appear,  and  the  proteid  con- 
stituents disappear.  In  a  later  communication  2  he  reported  the 
findings  in  the  autolyzed  spleens  of  two  cases  of  splenomyelog- 
enous  leukemia.  He  detected  among  the  products  guanin, 
xanthin,  hypoxanthin,  histidiu,  lysin,  alanin,  leucin,  tyrosin, 
thymin,  paralactic  acid,  and  ammonia ;  adenin  and  arginin  were 
not  found.  Autolysis  of  the  leukemic  bone-marrow  produced 
tyrosin,  leucin,  and  tryptophan.  In  fresh  leukemic  blood  he 
found  much  albumose  as  well  as  an  enzyme  digesting  casein  in 
alkaline  medium.  Autolysis  of  the  leukemic  spleen  is  more 
complete  than  that  of  the  normal  spleen,  v.  Jaksch,3  Erben,4 
and  others  have  noted  the  occurrence  of  peptones  and  albu- 
moses  in  leukemic  blood,  particularly  if  removed  postmortem. 
The  improvement  in  leukemia  that  follows  x-ray  treatment  is 
associated  with  an  increased  nitrogen  elimination,  probably  due 
to  autolysis  of  disintegrating  cells.5  (See  also  "  Leukemia," 
Chap,  xi.) 

Tumors. — Probably  because  of  the  great  amount  of  necro- 
sis that  is  constantly  going  on  in  all  malignant  growths,  with 
subsequent  digestion  of  the  dead  cells,  autolytic  products  are 
present  in  them  in  very  considerable  amounts.  This  was  first 

1  Hofmeister's  Beitr.,  1903  (3),  576. 

2  Ibid.,  1905  (7),  175. 

3Zeit.  f.  physiol.  Chem.,  1892  (16),  243. 

*  Zeit.  f.  klin.  Med.,  1900  (40),  282  ;  Zeit.  f.  Heilkunde,  1903  (24),  70  ;  Hof- 
meister's Beitr.,  1904  (5),  461. 

5  Musser  and  Edsall,  Univ.  Penn.  Med.  Bull.,  1905  (18),  174. 


102  ENZYMES 

demonstrated  by  Petry, l  who  found  that  carcinomata  of  the 
breast  contained  much  of  their  nitrogen  in  compounds  not 
coagulated  by  heat,  while  in  the  normal  gland  practically  all  is 
coagulable.  He  also  demonstrated  an  autolytic  property  in 
tumor  tissue,  showing  that  tumor  cells  do  not  differ  in  this 
respect  from  normal  cells. 

Neuberg 2  found  that  while,  according  to  other  observers,  most 
enzymes,  as  well  as  bacteria,  are  very  susceptible  to  the  action 
of  radium  rays,  the  autolytic  enzymes  of  cancer  cells  are  an 
exception,  for  cancer  tissue  exposed  to  radium  undergoes  autol- 
ysis  much  faster  than  cancer  tissue  not  exposed  to  radium.  He 
attributes  the  effects  of  radium  on  cancer  to  its  deleterious  effects 
on  the  oxidizing  and  other  enzymes  of  the  cells,  destroying  their 
activities,  which  results  in  destruction  of  the  cells  by  the  auto- 
lytic enzymes.3  A  cancer  of  the  stomach  was  found  to.  con  tain 
autolytic  enzymes  capable  of  digesting  lung  tissue  (pepsin  was 
excluded)  and  autolyzed  cancers  yielded  much  pentose.  Blu- 
menthal  and  Wolf4  believe  that  tumor  tissues  have  particularly 
active  autolytic  enzymes,  since  liver  tissue  added  to  tumor 
tissue  underwent  autolysis  much  more  rapidly  than  normal. 
Beebe 5  found  products  of  autolysis  constantly  present  in  several 
tumors ;  namely,  a  carcinoma  of  the  broad  ligament,  a  hyper- 
nephroma,  an  angiosarcoma,  and  a  round-cell  sarcoma. 

Micheli  and  Donati 6  attribute  the  hemolytic  properties  pos- 
sessed by  extracts  of  malignant  tumors  to  the  products  of  auto- 
lysis that  are  present,  which  Petry  has  also  demonstrated  to 
produce  hemolysis.  Emerson 7  attributes  the  disappearance  of 
HC1  from  the  gastric  juice  in  carcinoma  of  the  stomach  to  neu- 
tralization by  basic  products  of  autolysis,  a  hypothesis  that 
may  well  be  questioned.  (See  also  "Tumors,"  Chap,  xvii.) 

Various  other  intracellular  enzymes  have  been  described,  which  for 
the  most  part  have  as  yet  no  significance  in  pathology.  An  exception 
is  fibrin  ferment,  which  will  be  considered  fully  in  discussing  thrombosis. 
Ferments  coagulating  milk  seem  to  be  widely  spread  in  the  tissues. 

1  Zeit.  f.  physiol.  Chem.,  1899  (27),  398;  Hofmeister's  Beitr.,  1902  (2),  94. 

2Zeit.  f.  Krebsforschung,  1904  (2),  171 ;  Berlin,  klin.  Woch.,  1904  (41), 
1081  ;Ibid.,  1905  (42),  118. 

3  Wohlgemuth,  Berl.  klin.  Woch.,  1904  (41),  704,  found  that  autolysis  in 
tuberculous  lung  tissue  was  three  or  four  times  more  rapid  when  exposed  to 
radium  rays.  Heile  (Arch  klin.  Chir.,  1905  (77),  107)  looks  upon  the  favorable 
effects  of  x-rays  as  partly  produced  by  their  liberation  of  autolytic  enzymes 
from  the  leucocytes. 

4Med.  Klinik,  1905  (1),  No.  7. 

5Amer.  Jour.  Physiol.,  1904  (11),  139. 

6Riforma  med.,  1903  (19),  1037. 

7  Deut.  Arch.  klin.  Med.,  1902  (72),  415. 


AUTOLYSIS  IN  PATHOLOGICAL  PROCESSES  103 

The  precipitation  of  plastein  from  proteose  solution  by  organ  extracts 
(Niirnberg)  may  be  either  the  effect  of  a  coagulating  ferment  or  due  to 
reverse  action  of  the  proteases.  Ferments  splitting  specifically  maltose, 
starch,  and  nucleoproteids  have  been  described,  and  the  glycogenic 
ferment  is  probably  nearly  universally  present.  Other  enzymes  decom- 
posing amino-acids  into  ammonium  compounds  may  also  exist.  The 
enzymes  acting  specifically  upon  the  nucleic  acids  and  the  purin  bodies 
have  already  been  discussed. 


CHAPTER    IV 

THE  CHEMISTRY  OF   BACTERIA  AND  THEIR 
PRODUCTS 

STRUCTURE  AND  PHYSICAL  PROPERTIES  1 

IN  structure,  as  in  nearly  all  other  respects,  bacterial  cells 
stand  intermediate  between  the  cells  of  ordinary  plant  and  ani- 
mal tissues.  Their  cell  wall  seems  to  be  generally  more  highly 
developed  than  that  of  animal  cells,  and  less  so  than  the  wall 
of  most  plant  cells.  In  composition,  however,  the  wall  is  more 
closely  related  to  animal  than  to  vegetable  tissues.  The  much- 
vexed  question  as  to  the  existence  or  non-existence  of  a  nucleus 
seems  to  be  best  answered  by  Zettnow,  who  considers  that  the 
portion  of  the  bacterial  cell  usually  made  evident  by  ordinary 
staining  methods  consists  of  a  mixture  of  nuclear  substance 
(chromatin)  with  non-chromatic  substance  (entoplasm)  •  the  outer 
membrane,  which  requires  special  methods  for  its  satisfactory 
demonstration,  consists  of  a  modified  cytoplasm  (ectoplasm). 
Some  bacteria  consist  chiefly  of  chromatin  (e.  g.,  vibrios),  but 
the  proportion  of  the  different  elements  varies  greatly,  not  only 
in  different  varieties,  but  also  in  the  same  variety  under  differ- 
ent conditions.  The  fact  that  the  chromatin  is  not  aggregated 
into  the  usual  nuclear  form  may  be  ascribed  to  the  low  stage  of 
development  reached  by  bacteria  in  the  scale  of  evolution  ;  or, 
as  Vejdovosky  has  suggested,  to  the  extremely  rapid  rate  of 
cell  division  in  the  bacteria  which  prevents  the  chromatin  from 
appearing  in  the  resting  stage  which  a  nucleus  constitutes. 
Finer  structures  within  the  bacterial  cell  have  as  yet  been  only 
imperfectly  discerned. 

The  thickness  of  the  ectoplasm  varies  greatly  even  in  the  same 
species,  being  generally  greatest  in  older  cultures.  In  some 
forms  the  ectoplasm  may  constitute  one-half  of  the  total  mass 
of  the  cells.  The  capsule  seems  to  arise  through  a  swelling  of 
the  ectoplasm,  and  is  probably  present  in  at  least  a  rudimentary 
stage  in  all  bacteria  (Migula). 

1  In  this  chapter  references  will  not  generally  be  given  that  can  be  found  by 
consulting  Kolle  and  Wassermann's  Handbuch.  A  general  consideration  of 
the  Biology  of  the  Bacteria,  including  references  to  the  effects  of  light,  heat, 
osmotic  pressure,  etc.,  is  given  by  Miiller,  Ergeb.  der  Physiol.,  1904  (4),  138. 

104 


STRUCTURE  AND  PHYSICAL  PROPERTIES  105 

Plasmolysis  and  Plasmoptysis. — Under  conditions  of 
altered  osmotic  pressure  the  bacterial  cell  behaves  quite  similarly 
to  the  plant  cell  .l  If  placed  suddenly  in  a  solution  of  higher 
osmotic  pressure  than  the  one  in  which  it  has  been,  the  cell  con- 
tents shrink  away  from  the  cell  wall  (plasmolysis)  indicating 
that  there  exists  a  semipermeable  membrane  through  which 
water  passes  more  rapidly  than  salts.  If  the  change  in  osmotic 
pressure  is  gradual,  the  bacteria  accommodate  themselves  to  it  by 
the  slow  diffusion  of  the  salts  through  the  cell  membrane,  in- 
dicating that  it  is  not  absolutely  semipermeable.  Different 
bacteria  behave  differently,  some  bacteria  not  being  plasmolyzed 
by  solutions  that  plasmolyze  others.  As  a  rule,  old  bacteria 
plasuiolyze  more  rapidly  than  young,  and  in  some  varieties 
there  seems  to  be  a  spontaneous  plasmolysis,  to  which  has  been 
attributed  the  irregular  staining  of  diphtheria  and  tubercle 
bacilli,  the  polar  staining  of  plague  bacilli,  etc.  Plasmolysis 
occurs  only  in  living  bacilli,  but  does  not  necessarily  cause 
death. 

When  bacteria  pass  from  solutions  of  higher  osmotic  concen- 
tration into  solutions  of  lower  concentration,  the  phenomenon 
of  plasmoptysis  is  produced.  The  cell  contents  swell  until  the 
cell  wall  gives  way  at  some  point,  and  then  exude  as  glistening 
drops,  which  may  become  detached  from  the  wall  and  escape 
free  into  the  fluid.  Plasmoptysis  is  shown  best  by  bacteria 
that  have  been  grown  on  salt-rich  media  before  being  placed  in 
the  salt-free  fluid.  Not  all  varieties  of  bacteria  can  be  made  to 
undergo  this  change,  depending  probably  upon  a  greater  perme- 
ability of  their  cell  membranes  for  salts.  The  exposure  of  the 
naked  cell  contents  to  the  hypotonic  fluid  outside  the  cells 
makes  plasmoptysis  more  serious  for  bacterial  life  than  plasmol- 
ysis, but  how  often  either  process  plays  a  part  in  the  resistance 
of  infected  animals  against  bacteria  is  unknown. 

Chemotaxis. — Just  as  with  unicellular  animal  organisms, 
bacteria  respond  to  chemotactic  influences,  in  general  being 
attracted  by  substances  favorable  for  food,  such  as  peptone, 
dilute  potassium  salts,  etc.,  and  being  repelled  by  harmful  sub- 
stances, such  as  strong  acids  and  alkalies.  Attempts  have  been 
made  to  separate  different  organisms  in  mixed  cultures  by  means 
of  their  response  to  chemotaxis,  but  without  striking  success. 
It  is  possible  that  chemotaxis  may  play  a  part  in  the  localization 
of  bacteria  from  the  blood  stream  in  favorable  localities,  just  as 
leucocytes  are  attracted  to  points  of  injury,  but  this  has  not 

1  Literature,  see  Gotschlich,  Kolle  and  Wassermann's  Handbuch,  1903,  vol. 
1,  p.  62. 


106   CHEMISTRY  OF  BACTERIA  AND   THEIR  PRODUCTS 

been  demonstrated.   (The  chemotactic  influence  of  bacteria  upon 
leucocytes  is  discussed  in  Chapter  x.) 

CHEMICAL   COMPOSITION 

This  varies  greatly,  not  only  between  different  species,  but 
even  in  the  same  species  grown  on  different  media ;  in  this  re- 
spect bacteria  are  much  more  modified  by  their  environment  than 
are  higher  organisms.  Grown  on  a  salt-rich  medium  they  yield 
much  ash  ;  grown  on  a  peptone-rich  medium  they  contain  much 
proteid ;  grown  on  a  fat-rich  medium  they  contain  much  material 
soluble  in  ether.  Cholera  vibrios  grown  on  a  bouillon  medium 
contained  69.25  per  cent,  of  proteid,  and  25.87  per  cent,  of 
ash,  whereas  the  same  organism  grown  on  Uschinsky's  medium, 
which  contains  no  proteids  but  only  various  simple  chemical 
compounds,1  contained  but  35.75  per  cent,  of  proteid  and  13.7 
per  cent,  of  ash  (Cramer).  Even  in  the  same  medium  two 
different  strains  of  the  same  organism  may  show  equally  great 
differences  :  Two  strains  of  cholera  vibrios  grown  on  the  same 
medium  showed  respectively  65.63  per  cent,  and  34.37  per 
cent,  of  proteid.  It  is  evident,  therefore,  that  quantitative 
analyses  of  bacteria  show  nothing  as  to  their  nature,  and  on 
account  of  the  extreme  limits  of  their  variation  are  practically 
valueless. 

Qualitatively  the  variations  are  not  so  great — all  bacteria 
contain  proteids,  lipoid  substances,  and  salts,  of  which  phos- 
phates are  most  prominent  in  the  ash.  The  older  analyses  of 
bacterial  constituents  are  of  little  value.  Recent  studies  prove 
that  the  chief  constituent  of  the  cell  contents  is  a  true  nucleo- 
proteid (Iwanoff 2  )  containing  some  sulphur  and  iron  ;  probably 
many  of  the  "  pyogenetic  proteids,"  "  bacterial  toxalbumins," 
"  bacterial  caseins  "  of  earlier  investigators  are  true  nucleopro- 
teids.  In  a  water  bacillus  Nishimura  found  xanthin,  guanin, 
and  adenin,  indicating  the  presence  of  nucleoproteid ;  others 
have  found  that  bacterial  nucleoproteid s  split  off  pentoses,  as  do 
the  nucleoproteids  of  higher  cells.  Mary  Leach 3  found  evidence 
that  the  colon  bacillus  is  largely  made  up  of  nuclein  or  glyco- 
nucleoproteids,  but  contains  no  cellulose.  Other  proteids, 
namely,  globulins  and  nucleo-albuinins,  have  also  been  described 

1  Uschinsky's   medium  is:    Water,  1000   parts;    glycerin,  30-40;  sodium 
chloride,  5-7  ;  calcium  chloride,  0.1 ;  magnesium  sulphate,  0.2-0.4;   di-potas- 
sium-phosphate,  0.2-0.25  ;  ammonium  lactate,  6-7  ;  sodium  asparaginate,  3-4 
parts. 

2  Hofmeister's  Beit.,  1902  (1),  524. 

3  Jour.  Biol.  Chem.,  1906  (1),  463.     Full  bibliography  on  Chemistry  of  Bac- 
teria. 


CHEMICAL  COMPOSITION  107 

as  constituents  of  the  bacterial  plasma.  The  slimy  material 
produced  in  cultures  by  some  varieties  of  bacteria  is,  at  least 
for  certain  forms,  a  body  closely  related  to  or  identical  with 
true  mucin.1  Heirn2  considers  that  anthrax  bacilli  also  pro- 
duce niucin. 

Bacterial  Carbohydrates. — Likewise  the  earlier  descriptions 
of  cellulose  or  hemicellulose  in  the  cell  membrane  of  bacteria  are 
undoubtedly  incorrect.  Numerous  investigations  have  shown 
that  the  insoluble  bacterial  cell  wall  consists  chiefly  of  chitin, 
which  on  being  split  with  acids  yields  80  to  90  per  cent,  of  the 
nitrogenous  carbohydrate,  glucosamin.  The  distinction  is  a 
very  important  one,  since  cellulose  is  a  typically  vegetable  prod- 
uct, while  chitin  is  equally  typically  animal  in  origin,  being 
found  chiefly  in  the  shells  of  lobsters  and  crabs,  the  wings  and 
coverings  of  flies,  beetles,  etc.  Chitin  seems  to  be  an  amino- 
derivative  of  a  carbohydrate,  a  polymeric  form  of  some  simpler 
compound,  just  as  cellulose  is  a  polymer  of  a  simpler  carbohy- 
drate. 

Other  carbohydrates  seem  to  be  scanty  in  the  bacterial  cell. 
Cramer  could  find  no  glucose  in  any  variety,  although  there  are 
some  bacteria  that  contain  material  reacting  like  starch  with 
iodin.  Levene,3  however,  found  in  B.  tuberculosis  a  substance 
with  the  properties  of  glycogen. 

Bacterial  Fats. — By  staining  methods,  fats  have  been  recog- 
nized in  many  species,  and  by  extraction  with  fat  solvents 
lecithin,  cholesterin,  simple  fats,  and  specific  bacterial  fats  have 
been  isolated ;  this  is  particularly  true  of  B.  tuberculosis,  which 
owes  its  characteristic  staining  properties  to  the  specific  fat-like 
bodies  which  make  up  a  large  proportion  of  its  entire  mass.4 
Numerous  studies  of  these  fats  of  B.  tuberculosis  have  been 
made5  and  by  using  diiferent  extractives,  from  20  to  40  per 
cent,  of  the  entire  weight  of  the  bacilli  has  been  found  soluble 
in  fat  solvents.  Kresling  found  that  the  substance  soluble 
in  chloroform  had  the  following  composition  : 

Free  fatty  acid 14.38  per  cent. 

Neutral  fats  and  fatty  acid  esters 77.25   "      " 

Alcohols  obtained  from  fatty  acid  esters     ....  39.10    "      " 

Lecithin 0.16   "      " 

Substances  soluble  in  water 0.73   "      " 

1  Kettger,  Jour.  Med.  Kesearch,  1903  (10),  101. 

2  Munch,  med.  Woch.,  1904  (51),  426. 
8  Jour.  Med.  Eesearch,  1901  (6),  135. 

4  See  Camus  and  Pagniez,  Compt.  Kend.  Soc.  Biol.,  1905  (59),  701. 

8  For  literature  see  Bulloch  and  Macleod,  Jour,  of  Hygiene,  1904  (4),  1. 


108    CHEMISTRY  OF  BACTERIA  AND   THEIR  PRODUCTS 

Bulloch  and  Macleod  found  that  ethereal  extracts  did  not  con- 
tain the  acid-fast  substances  which  they  consider  to  be  a  wax-like 
alcohol,  soluble  in  hot,  but  insoluble  in  cold  absolute  alcohol  or 
in  ether.  The  simple  fats  seem  to  be  formed  by  oleic,  isocetinic, 
and  myristinic  acids,  and  there  is  some  lauric  acid  in  the  form  of 
a  soap.  Cholesterin  is  probably  present,  and  there  are  also 
lipochromes  giving  the  cultures  their  color. 

By  staining  with  sudan  III,  Sata l  demonstrated  fats,  not 
only  in  the  acid-fast  bacilli,  but  also  in  anthrax,  Staphylococciis 
aureus,  B.  mucosus,  and  actinomyces  ;  but  not  in  diphtheria, 
pseudo-diphtheria,  plague,  cholera,  and  chicken  cholera  bacilli, 
or  in  members  of  the  colon  group.2  Only  a  few  bacteria  form 
fat  on  agar  free  from  glycerin,  but  potato  is  a  favorable  medium. 

Spores  differ  from  their  parent  bacteria  in  containing  a  much 
greater  proportion  of  the  solid  constituents  and  less  water.  In 
molds  Drymont  found  that  the  spores  contained  over  60  per 
cent,  of  dry  substance,  and  almost  all  the  water  was  so  held  as 
to  resist  drying  by  temperatures  below  boiling ;  the  dry  sub- 
stance is  very  rich  in  proteid  and  poor  in  salts.  The  wall  of 
the  spore  consists  of  a  "  cellulose-like "  substance  (probably 
chitinous)  and  a  very  hygroscopic  extractive  matter.  The  great 
resistance  of  spores  to  drying  and  to  heat  can  be  readily  under- 
stood in  view  of  these  facts.  Flagella  also  seem  to  be  composed 
of  a  relatively  condensed  proteid. 

Staining1  Reactions. — The  staining  reactions  of  bacterial 
cells  are  much  as  if  the  bacteria  consisted  entirely  of  chromatin, 
so  that  at  one  time  the  theory  prevailed  that  bacteria  consisted 
merely  of  a  nucleus  and  a  cell  wall,  without  any  true  cytoplasm. 
The  demonstration  of  abundant  nucleoproteid  in  the  contents  of 
bacterial  cells  explains  their  staining  affinity  for  basic  anilin 
dyes.  Owing  to  some  unknown  differences  in  composition,  not 
all  bacteria  are  stained  equally  well  by  the  same  basic  dyes. 
Although  the  staining  of  bacteria  depends  upon  a  chemical  re- 
action between  the  nucleoproteids  and  the  basic  dye,  yet  the 
combination  is  not  usually  a  firm  one,  being  readily  broken  by 
weak  acids  in  most  cases.  That  the  decolorization  of  bacteria 
depends  upon  dissociation  of  the  dye-proteid  compound  is  shown 
by  the  fact  that  absolutely  water-free  alcohol  will  not  decolorize 
dry  bacteria,  nor  do  water-free  alcoholic  solutions  of  dyes  stain 
dehydrated  bacteria. 

1Cent.  f.  allg.  Path.,  1900  (11),  97. 

2  Auclair  (Arch.  He'd.  Exper.,  1903  (15),  725)  contends  that  the  ether  and 
chloroform  extracts  of  many  pathogenic  bacteria  contain  important  toxic  sub- 
stances. Holmes  (Guy's  Hosp.  Reports,  1905  (59),  155)  states  that  injection 
of  fatty  acids  from  tubercle  bacilli  into  rabbits  causes  a  lymphocytosis. 


BACTERIAL  ENZYMES  109 

Gram's  method  of  staining  depends  on  the  formation  of  an 
iodin-pararosanilin-proteid  compound  which  is  not  easily  disso- 
ciated by  water  in  the  case  of  bacteria  that  stain  by  this  method, 
and  which  is  readily  dissociated  and  dissolved  out  in  the  case 
of  bacteria  that  do  not  retain  the  stain.  Only  pararosanilin 
dyes  (gentian  violet,  methyl  violet,  victoria  blue)  form  such 
combinations,  the  rosanilin  dyes  (fuchsin,  methylene-blue)  not 
being  suitable. 

The  acid-fast  bacilli  (leprosy,  tubercle,  and  allied  forms)  owe 
their  characteristic  resistance  to  both  staining  and  destaining 
processes,  to  their  high  fat  content,  which  modifies  greatly  the 
penetration  by  stains  and  reagents.  It  is  said  that  organisms 
not  ordinarily  acid-fast  may  be  made  so  by  increasing  their  fat 
contents  by  growing  them  on  fat-rich  media.  According  to 
Bulloch  and  Macleod  1  the  acid-fastness  of  the  tubercle  bacillus 
depends  not  on  the  ordinary  ether-soluble  fats,  but  on  a  high 
molecular  alcohol  of  undetermined  composition,  soluble  in  boil- 
ing absolute  alcohol. 

BACTERIAL  ENZYMES 

The  metabolic  processes  of  bacteria  seem  to  be  closely  depend- 
ent upon  enzyme  action,  just  as  with  higher  cells.2  Liquefaction 
of  gelatin  is  a  familiar  example  of  the  enzyme  action  of  bacteria  ; 
and  since  the  filtered  cultures  of  liquefactive  bacteria  are  also 
capable  of  digesting  gelatin,  the  enzymes  are  evidently  excreted 
from  the  cells.  Dead  bacteria,  killed  by  thymol  or  by  other 
antiseptics  that  do  not  destroy  proteolytic  enzymes,  will  also 
digest  gelatin.  Numerous  investigations  have  established  the 
wide-spread  occurrence  of  many  soluble  enzymes  both  in  bacteria 

1  Loe.  cit. 

2  One  must  distinguish  between  "enzymes"  and  "ferments,"  although  since 
most  of  the  characteristic  fermentative  actions  of  yeast  and  other  cells  have 
been  found  to  be  produced  by  intracellular  enzymes,  the  distinction  is  not 
always  easy  to  make.     Gotschlieh  (Kolle  and  Wassermann's  Handbuch,  vol.  i, 
p.  104)  would  distinguish  them  as  follows:     "Fermentation  is  a  direct  func- 
tion of  the  living  protoplasm,  and  serves  as  its  source  of  energy."     "  Enzyme 
action  is  not  directly  dependent  on  the  living  protoplasm,  and  does  not  serve 
the  organism  as  a  source  of  energy."     Exception  can  readily  be  taken  to  these 
definitions,  however,  for  the  latest  indications  are  that  nearly  all  of  the  separate 
processes  that  go  to  make  up  the  process  of  fermentation  are  enzyme  processes. 
Fermentation  may,  therefore,  be  looked  upon  as  the  action  of  living  organisms, 
being  the  sum  of   the  action  of  the  enzymes  of  the  organisms  together  with 
certain  other  chemical  processes  not  brought  about  by  enzymes.     In  general, 
the  distinction  is  made  chiefly  on  the  ground  that  we  can  stop  fermentative 
processes  by  means  of  certain  antiseptics  that  kill  the  causative  organisms,  but 
which  do   not   greatly  impair  the  enzymes.     Even  this  distinction   is  more 
quantitative  than  qualitative,  for  very  dilute  solutions  of  enzymes  are  nearly 
as  susceptible  to  antiseptics  as  are  bacteria  (Kaufmann,  Zeit.  physiol.  Chem., 
1903  (39),  434). 


110   CHEMISTRY  OF  BACTERIA  AND   THEIR  PRODUCTS 

and  in  their  secretions,  indicating  that  bacterial  cells  are  as 
dependent  on  enzymes  for  the  production  of  their  metabolic 
activities  as  are  higher  types  of  cells,  and  that  these  enzymes  are 
not  only  present  as  intracellular  constituents,  but  that  they  also 
escape  from  the  cells. 

The  diffusion  method  of  Wijsman,  or,  as  it  is  more  frequently 
called,  auxanographic  method  of  Beijerinck,  offers  a  relatively 
simple  means  of  detecting  the  presence  of  extracellular  bacterial 
enzymes.  Eijkman  l  in  particular  has  used  this  method,  which 
consists  of  mixing  agar  with  milk,  or  starch,  or  whatever  material 
is  to  serve  as  the  indicator  of  the  enzyme  action  ;  the  agar  is  then 
inoculated  with  bacteria  and  plated  (or  else  the  bacteria  are  inocu- 
lated as  a  streak  on  the  surface  of  the  agar).  About  each  colony 
there  will  appear  a  zone  of  clearing  in  the  medium,  if  it  produces 
enzymes  digesting  the  admixed  substance.  By  this  means  Eijk- 
man found  that  all  bacteria  that  produce  enzymes  digesting  gela- 
tin also  digest  casein,  and  those  that  do  not  digest  gelatin  are 
equally  without  effect  on  casein ;  therefore,  it  is  probably  the 
same  enzyme  that  digests  both.  As  the  hemolytic  action  of 
bacteria  is  not  constantly  related  to  their  gelatin-dissolving  prop- 
erty, the  hemolysis  probably  is  produced,  at  least  in  some  cases, 
by  other  means  than  the  proteolytic  enzymes.  A  few  pathogenic 
bacteria  (anthrax,  cholera)  digest  starch,  and  B.  pyocyaneus, 
Staphylococcus  pyogenes  aureus,  and  B.  prodigiosus  all  produce 
fat-splitting  enzymes.  B.  pyocyaneus,  he  found,  digested  elastic 
tissue  readily,2  as  also  did  a  bacillus  resembling  B.  subtilis 
obtained  from  the  tissue  of  a  gangrenous  lung.  The  following 
table  by  Buxton 3  gives  an  idea  of  the  distribution  of  enzymes  in 
bacterial  secretions  as  determined  by  the  auxanographic  method  : 

ENZYMES  HYDRATING  CARBOHYDRATES 

Amylase.  Maltase.  Invertase.  Lactase.    Inulase. 

1.  Anthrax      +  + 

2.  Cholera + 

3.  Coli  communis — 

4.  Typhoid 

5.  Diphtheria 

6.  Staph.  pyogenes  aureus    ...      — 

7.  Lactis  aerogenes +  + 

8.  Pyocyaneus — 

9.  Violaceus ... 

10.  Mycoides +  -f 

11.  Prodigiosus 

12.  Saccharomyces  niger     ....      —  + 

13.  Saccharomyces  neoformans  .    . 

14.  Aspergillus  niger -f-  -j- 

15.  Aspergillus  oryzoe -j-  ~h 

1Cent.  f.  Bakt.,  1901  (29),  841. 

2  Cent.  f.  Bakt.,  1903  (35),  1. 

3  American  Med.,  1903  (6),  137. 


BACTERIAL   ENZYMES 


111 


PROTEOLYTIC  ENZYMES,  DIGESTING 


Mi 

Ik. 

Egg- 

Red 

Coagul. 

Diges- 
tion. 

Gela- 
tin. 

Serum. 

men. 

Fibrin. 

blood- 
corpus- 
cles. 

1  Anthrax 

4- 

-{- 



-f 

+ 

-f- 

9  Cholera  .... 

4- 

4- 

4- 

+ 

+ 

-j- 

4- 

3.  Coli  communis    .    .    • 
4.  Staph.  pyogenesaureus 
5.  Streptococcus      pyog- 

4- 

+ 

+ 

+ 
-f 

6.  Pyocyaneus  .... 
7.  Violaceus  
8.  Mycoides  

•f 

+ 

+ 

4- 
4. 

+ 

-f 
+ 

4- 

+ 
-f 

+ 

+ 

4- 

4- 

? 

+ 
+ 
-f- 

10.  Aspergillus  niger  .    . 
11.  Aspergillus  oryzoe  . 

+ 

+ 

•f 

+ 
+ 

+ 

+ 

Rennin  is  produced  by  many  bacteria,  as  is  shown  by  their 
coagulating  milk,  independent  of  any  acid  reaction.1 

An  interesting  observation  made  by  Schmailowitsch 2  is  that 
the  amount  and  nature  of  enzymes  produced  by  bacteria  is  modi- 
fied by  the  amount  and  nature  of  their  food.  When  they 
receive  no  food,  they  secrete  no  enzymes ;  when  grown  on  pro- 
teid-rich  media  they  produce  much  proteolytic  enzyme ;  grown 
on  a  carbohydrate  medium  they  produce  chiefly  amylolytic  en- 
zymes. This  observation  recalls  Pawlow's  demonstration  of  the 
similar  influence  of  the  quality  of  food  upon  the  proportion  of 
the  various  digestive  enzymes  contained  in  the  pancreatic  juice ; 
under  proteid  diet  the  trypsin  is  in  excess  ;  under  starch  diet  the 
amylopsin  is  in  excess,  etc.  Abbott  and  Gildersleeve 3  have 
corroborated  this  statement,  finding  that  bacteria  grown  on  gel- 
atin produce  much  more  active  gelatin-dissolving  enzyme  than 
do  bacteria  grown  on  bouillon.  This  phenomenon  they  would 
explain  on  the  basis  of  Welch's  hypothesis  that  bacteria  react 
to  chemical  substances  by  producing  antagonistic  substances,  just 
as  higher  organisms  do  under  similar  conditions.  It  is  probably 
closely  related  to  the  difference  of  composition  observed  in  bac- 
teria grown  on  different  media  (vide  supra). 

In  general,  bacterial  proteolytic  enzymes  resemble  trypsin 
more  closely  than  they  do  pepsin,  acting  best  in  an  alkaline 
medium  ;  but  the  enzymes  extracted  from  bacterial  cultures  are 
very  feeble  as  compared  with  pancreatic  trypsin.  Abbott  and 
Gildersleeve  found  that  the  gelatin-dissolving  enzyme  of  bac- 
teria resists  a  temperature  of  100°  C.  for  as  long  as  fifteen  to 

1  Contradicted  by  DeWaele,  Cent.  f.  Bakt.,  1905  (39),  353. 

2  Wratschebnaja  Gazetta,  1902,  p.  52. 

3  Jour.  Med.  Research,  1903  (10),  42. 


112   CHEMISTRY  OF  BACTERIA  AND   THEIR  PRODUCTS 

thirty  minutes  (disagreeing  with  Fermi).  Schmailowitsch 1 
states  that  some  bacteria  produce  an  enzyme  acting  in  acid 
medium  upon  gelatin  but  not  upon  albumin,  and  this  enzyme 
carries  the  digestion  only  as  far  as  the  gelatin-peptone  stage, 
whereas  the  enzymes  acting  in  an  alkaline  medium  carry  the 
splitting  through  to  leucin,  tyrosin,  etc.  Plenge 2  suggests  that 
there  is  a  special  enzyme  digesting  nucleoproteids.  The  bac- 
terial amylolytic  enzyme  acts  like  ptyalin. 

Cacace3  investigated  the  splitting  products  of  gelatin  and 
coagulated  blood  when  digested  by  B.  anthracis,  Staph.  pyogenes 
aureus,  and  Sarcina  aurantiaca,  and  found  that  proteoses  and 
peptone  are  produced,  which  disappear  in  the  later  stages  of 
digestion.  Rettger 4  found  leucin,  tyrosin,  tryptophan,  as  well 
as  phenols,  skatol,  indol,  aromatic  oxy-acids,  and  mercaptan, 
among  the  products  of  bacterial  decomposition  of  egg-albumen 
and  meat ;  proteoses  and  peptones  appear  in  the  early  stages, 
but  later  disappear,  as  also  eventually  do  the  leuciu,  tyrosin,  etc. 
Cholin  has  also  been  found  in  the  products  of  atitolysis.5  Mav- 
rojannis 6  found  that  some  bacteria  digest  gelatin  only  as  far  as 
the  gelatose  stage  (which  is  determined  by  its  being  hardened 
by  formalin),  while  others  carry  the  digestion  to  peptones  and 
non-proteid  substances  which  cannot  be  hardened  by  formalin. 

The  digestive  power  of  the  nitrates  of  cultures  and  of  killed 
bacteria  is  far  less  than  that  of  the  living  bacteria  (Knapp 7 ). 
Streptococci  digest  proteids  of  exudates  feebly,  staphylococci 
more  rapidly,  and  colon  bacilli  are  still  more  active.  He  could 
find  no  relation  between  the  proteolytic  power  of  the  bacteria 
and  the  severity  of  the  infection  from  which  they  came. 

Immunity  against  bacterial  enzymes  may  be  secured  as 
it  is  against  other  enzymes.  Abbott  and  Gildersleeve 8  found 
that  by  injections  into  animals  of  proteolytic  bacterial  nitrates 
which  were  only  slightly  toxic,  the  serum  of  the  animals 
acquired  a  slight  but  specific  increase  in  resistance  to  the  proteo- 
lytic enzymes  of  the  filtrates.  Normal  serum  contains  a  cer- 
tain amount  of  enzyme-resisting  substance.  Other  observers 
have  found  that  immunization  against  living  or  dead  bacteria 
leads  to  the  production  of  substances  antagonistic  to  their 

1  Abst.  in  Biochem.  Centr.,  1903  (1),  230  ;  see  also  DeWaele,  Cent.  f.  Bakt, 
1905  (39),  353. 

2  Zeit.  f.  physiol.  Chem.,  1903  (39),  190. 

3  Cent.  f.  Bakt.,  1901  (30),  244. 

4  Amer.  Jour,  of  Physiol.,  1903  (8),  284. 

6Kutscher  and  Lohmann,  Zeit.  physiol.  Chem.,  1903  (39),  313. 

6  Zeit.  Hygien.  u.  Infektionskr. ,  1903  (45),  108. 

7  Zeit.  f.Heilk.  (Chir.  Abt.)  1902  (23),  236. 

8  Loc.  tit. 


BACTERIAL  ENZYMES  113 

enzymes,  but  the  degree  of  resistance  acquired  is  never  great, 
v.  Dungern  l  found  that  the  serum  of  animals  infected  with 
various  bacteria  prevented  digestion  of  gelatin  by  the  enzymes 
obtained  from  cultures  of  the  same  species  of  bacteria.  He 
applied  this  fact  to  the  diagnosis  of  infectious  conditions,  find- 
ing that  the  serum  of  a  patient  with  osteomyelitis  was  over 
twenty  times  as  strongly  inhibitory  to  staphylococcus  enzymes 
as  was  serum  of  normal  persons.  The  reaction  is  specific, 
cholera  vibrio  enzymes  not  being  inhibited  to  any  corresponding 
degree. 

Autolysis  of  Bacteria. — Autolysis  occurs  also  in  bacteria, 
their  proteolytic  enzymes  digesting  the  cell  substance  whenever 
the  organisms  are  killed  by  agents  (chloroform,  toluol,  etc.)  that 
do  not  destroy  these  enzymes.  Even  the  absence  of  food  leads 
to  the  same  result,  presumably  because  the  normally  existing 
autolytic  processes  are  not  counteracted  by  synthesis  of  new 
proteid  material ;  hence,  autolysis  occurs  when  bacteria  are 
placed  in  salt  solution  or  distilled  water.  Although  it  had  been 
known  for  many  years  that  yeast  cells  digest  one  another  when 
there  is  nothing  else  for  them  to  live  upon,  the  first  definite 
study  of  bacterial  autolysis  seems  to  have  been  made  by  Levy 
and  PfersdorfF2  and  Conradi.3  The  former  digested  anthrax 
bacilli  (in  whose  bodies  are  contained  rennin,  lipase,  and  pro- 
tease) under  toluol  for  several  weeks,  and  obtained  a  slightl^ 
toxic  product.  Conradi  permitted  dysentery  bacilli  and  typhoid 
bacilli  to  digest  themselves  in  normal  salt  solution  for  twenty- 
four  to  forty-eight  hours  at  37°  C.,  and  obtained  in  this  way 
the  soluble,  highly  poisonous  endotoxins  of  the  bacteria,  which 
are  liberated  by  the  destruction  of  the  bacterial  structure  by  the 
autolytic  enzymes.  Longer  autolysis  results  in  the  destruction 
of  the  endotoxins  themselves  by  the  enzymes.  Rettger  4  found 
among  the  autolytic  products  of  bacteria,  leucin,  tyrosin,  basic 
substances,  and  phosphoric  acid.  Under  favorable  conditions 
complete  autolysis  can  occur  in  two  to  ten  days. 

Brieger  and  Mayer 5  found  that  at  room  temperature  (15°  C.) 
practically  no  autolysis  occurs  with  typhoid  bacilli  in  distilled 
water,  and  the  soluble  products  thus  obtained  are  quite  non- 
toxic,  although  if  injected  into  animals  they  give  rise  to  the 
production  of  agglutinins  and  bacteriolysins.  Bertarelli6  has 

1  Munch,  med.  Woch.,  1898  (45),  1040. 
2Deut.  med.  Woch.,  1902  (28),  879. 
*Ibid,,  1903  (29),  26. 

4  Jour.  Med.  Kesearch,  1904  (13),  79. 

5  Deut.  med.  Woch.,  1904  (30),  980. 

6  Cent.  f.  Bakt.,  1905  (38),  584. 


114   CHEMISTRY  OF  BACTERIA  AND  THEIR  PRODUCTS 

used  the  products  of  autolysis  of  cholera  vibrios  successfully  in 
the  production  of  immunity,  and  states  that  the  products  of 
autolysis  consist  largely  of  nucleins. 

It  is  probable  that  in  every  culture  bacteria  are  constantly 
being  destroyed,  either  by  their  own  enzymes  or  by  the  proteo- 
lytic  enzymes  of  the  other  bacteria.  Some  bacteria  are  much 
more  rapidly  autolyzed  than  others,  cholera  vibrios,  colon, 
typhoid,  and  dysentery  bacilli  being  rapidly  digested,  while 
tubercle  bacilli  are  very  little  and  slowly  autolyzed.  Conradi l 
who  has  shown  that  certain  products  of  autolysis  of  tissues  are 
bactericidal,  believes  that  also  in  cultures  powerfully  bacteri- 
cidal substances  are  produced  through  autolysis  of  the  bacteria. 
This,  he  thinks,  accounts  for  the  decrease  in  numbers  of  living 
bacteria  that  always  sets  in  after  a  short  period  of  growth  on 
artificial  media ;  for  example,  the  bacteria  in  a  culture  of  cholera 
vibrios  increase  in  number  for  about  twelve  hours,  and  then  their 
number  steadily  decreases.  When  cultures  that  have  ceased  to 
grow  are  placed  in  a  diffusion  membrane,  so  that  the  autolytic 
products  can  escape,  growth  promptly  begins  again.2  It  has 
been  found  by  Turro4  that  extracts  from  various  tissues  con- 
taining autolytic  enzymes  can  digest  bacterial  cells.4  It  is  very 
possible  that  the  endotoxins  contained  within  such  pathogenic 
bacteria  as  typhoid  and  cholera  are  liberated  through  digestion 
of  the  bacteria,  either  by  autolysis  or  by  the  enzymes  of  the 
leucocytes  and  tissues  of  the  organism  that  they  have  infected. 
These,  and  a  number  of  other  bacteria,  produce  no  soluble 
toxins  that  diffuse  from  the  cells,  as  do  diphtheria  and  tetanus 
toxin,  and  it  is  difficult  to  explain  the  toxic  effects  these  bacteria 
produce  without  assuming  that  their  intracellular  toxins  are 
liberated  in  some  such  way.  It  is  also  quite  probable  that  the 
enzymes  found  in  filtrates  from  bacterial  cultures  are  liberated 
from  the  bacterial  cells  only  when  these  have  been  autolyzed.5 
With  the  possible  exception  just  mentioned,  there  is  little  evi- 
dence that  the  bacterial  enzymes  play  any  important  r6le  in 
infectious  diseases.  They  may  be  a  slight  factor  in  the  diges- 

1  Munch,  raed.  Wochenschr.,  1905  (52),  1761. 

2  The  conclusions  of  Conradi  are  contested  by  Manteufel,  Berl.  klin.  Woch., 
1906  (43),  313. 

3  Cent.  f.  Bakt.,  1902  (32),  105. 

4Sigwart  (Arb.  a.  d.  Path.  Inst.  Tubingen,  1902  (3),  277)  found  that  tryp- 
sin  and  pepsin  (without  acid)  do  not  injure  living  anthrax  bacilli. 

5  Emmerich  and  Loew  (Zeitschr.  f.  Hyg.,  1899  (31),  1),  having  found  that 
pyocyanase  is  capable  of  destroying  and  digesting  other  bacteria  than  pyocy- 
aneus,  suggested  that  it  might  be  a  potent  factor  in  producing  artificial  immu- 
nity. Their  rather  remarkable  hypotheses  have  been  much  contested,  and  are 
of  questionable  value.  (See  Petrie,  Jour,  of  Pathol.  and  Bacteriol.,  1903  (8), 
200  ;  also,  Kettger  (Jour.  Infectious  Diseases,  1905  (2),  562). 


POISONOUS  BACTERIAL  PRODUCTS  115 

tion  of  tissue  and  exudates  in  suppuration,  but  as  compared 
with  the  leucocytic  enzymes  their  influence  is  probably  minute ; 
beyond  this  they  have  no  apparent  influence  upon  their  host, 
and  are  chiefly  concerned  in  the  metabolism  of  the  bacteria. 
The  proteoses  and  peptones  produced  by  bacterial  action  do  not 
seem  to  be  any  more  toxic  than  those  produced  by  pepsin  and 
trypsin. 

POISONOUS  BACTERIAL  PRODUCTS 

Almost  without  exception  all  the  harm  that  bacteria  do  is 
brought  about  by  means  of  the  chemical  substances  produced  in 
one  way  or  another  by  their  metabolic  processes.  Animal 
parasites  may  do  harm  mechanically,  but  with  the  possible 
exception  of  the  effects  of  capillary  emboli  (especially  with 
anthrax),  bacteria  produce  all  their  effects  through  chemical 
means.  The  poisonous  chemical  substances  produced  by  bac- 
teria may  be  grouped  into  four  classes  : 

I.  Products  of  the  decomposition  of  the  media  upon  which 
the  bacteria  are  growing ;  among  these  the  best  known  are  the 
ptomains. 

II.  Soluble  poisons  manufactured  by  the  bacteria,  and  se- 
creted from  the  cell  into  its  surrounding  media — the  true  toxins. 

III.  Poisons  manufactured  by  the   bacteria   which  do  not 
escape  from  the  normal  cell,  but  which  are  as  specific  in  their 
poisonous  properties  as  the  true  toxins ;  because  of  their  intra- 
cellular  situation  they  are  called  endotoxins. 

IV.  Poisonous  proteid  constituents  of  the  bacterial  cell,  which 
form  part  of  the  cell  protoplasm,  but  which  are  not  soluble  and 
the  poisonous  effects  of  which  are  not  specific  and  not  usually 
responsible  for  the  disease ;  these  are  called  bacterial  proteids. 

PTOMAINS 

Ptomains,  the  soluble  basic  nitrogenous  substances  that  are 
found  in  the  medium  in  which  bacteria  have  been  growing,  were 
the  first  bacterial  products  that  were  recognized,  and  for  some 
time  it  was  believed  that  it  was  through  the  production  of  such 
alkaloid -like  substances  that  bacteria  caused  disease,  just  as 
poisonous  plants  owe  their  effects  to  poisonous  alkaloids.  It 
was  soon  found,  however,  that  the  ptomains  that  could  be  iso- 
lated from  cultures  of  pathogenic  bacteria  were  insufficient  by 
themselves  to  cause  the  poisonous  effects  that  such  cultures 
produced  when  injected  into  animals.  The  isolated  ptomains 
were  not  only  far  less  poisonous  than  the  original  culture,  but 
furthermore  they  did  not  produce  the  symptoms  and  anatomical 


116    CHEMISTRY  OF  BACTERIA  AND   THEIR  PRODUCTS 

changes  characteristic  of  the  diseases  that  the  pathogen ic  organ- 
ism caused.  Furthermore,  the  majority  of  ptomai'ns  are  not 
very  poisonous,  and  highly  poisonous  ptomai'ns  may  be  produced 
by  non-pathogenic  bacteria.  As  a  result,  the  work  on  ptomains, 
which  twenty  years  ago  occupied  many  laboratories  and  prom- 
ised to  reveal  the  entire  chemistry  of  bacterial  intoxication,  has 
now  been  almost  completely  dropped.  The  interest  in  ptomai'ns 
is  by  no  means  entirely  historical,  however,  for  poisonous 
ptomai'ns  at  times  do  enter  the  body  and  cause  illness,  some- 
times even  death.  The  close  chemical  resemblance  to  vegetable 
alkaloids  of  some  of  the  ptomai'ns  that  may  arise  in  decom- 
posing corpses,  makes  them  of  great  importance  to  chemists 
searching  for  the  cause  of  death  in  cases  of  supposed  poisoning. 
Therefore  the  most  essential  features  of  the  ptomai'ns  and  their 
chief  known  relations  to  intoxications  will  be  briefly  discussed, 
referring  the  reader  for  a  full  consideration  to  Vaughan  and 
Novy's  "  Cellular  Toxins."  l 

The  ptomai'ns  owe  their  basic  character  to  nitrogen-containing 
radicals,  principally  amino-groups,  and  hence  are  formed  from 
nitrogenous  substances,  chiefly  proteids,  which  contain  their 
nitrogen  in  the  amino  form.  Probably  most  ptomai'ns  arise 
from  the  decomposition  of  the  proteid  medium  upon  which  the 
bacteria  grow,  although  undoubtedly  part  of  the  ptomains  is 
also  formed  from  the  destruction  of  the  bacterial  cells  them- 
selves ;  how  large  a  part  of  the  ptomains  is  formed  by  intra- 
cellular  bacterial  processes  and  how  much  by  cleavage  of  the 
proteids  of  the  media  by  extracellular  bacterial  enzymes  is 
unknown.  The  structure  of  the  ptomai'ns  shows  them  to  be  very 
closely  related  to  the  amino-acids  obtained  by  cleavage  of  the 
proteid  molecule  by  enzymes  and  other  hydrolytic  agencies ; 
hence  it  is  probable  that  ptomains  are  produced  by  secondary 
changes  in  the  elementary  nitrogenous  "  building  stones  "  of  the 
proteid  molecule,  the  amino-acids.  Presumably  these  secondary 
changes  result  from  the  action  of  special  enzymes  upon  the 
amino-acids,  e.  g.}  urease  (a  bacterial  enzyme)  splits  urea  into 
ammonia  and  carbon  dioxide ;  but  possibly  they  are  partly 
due  to  interaction  of  the  cleavage  products  upon  one  another. 
Most  of  the  ptomains  are  free  from  or  poor  in  oxygen,  hence 
reduction  processes  are  probably  important  in  their  production. 
The  poisonous  ptomains,  which  are  decidedly  in  the  minority 
among  the  entire  group,  are  themselves  subject  to  decomposition, 
being  most  abundant  in  the  cultures  after  a  certain  period  of 
time,  and  then  decreasing  in  amount.  Very  old  cultures  show 
1  Philadelphia,  1902. 


PTOMAINS  117 

almost  none  of  the  higher  molecular  forms  of  nitrogen,  such  as 
ptomains,  these  substances  having  been  changed  into  ammonium 
and  nitrate  compounds.  In  sharp  contradistinction  to  the  toxins, 
the  ptomains  are  by  no  means  specific.  No  matter  upon  what 
medium  diphtheria  bacilli  grow,  the  toxin  produced  has  qualita- 
tively the  same  properties,  whereas  the  nature  of  the  ptomai'ns 
depends  not  only  upon  the  nature  of  the  bacteria  producing  them, 
but  also  even  more  upon  the  sort  of  soil  upon  which  the  bacteria 
are  grown,  the  temperature,  the  duration  of  the  process,  and  the 
quantity  of  oxygen  furnished.  The  same  organism  may  pro- 
duce totally  different  ptomains  when  grown  on  different  media 
or  under  different  conditions.  Another  essential  difference  is 
that  we  cannot  obtain  an  immune  serum,  antagonizing  the  action 
of  ptomains,  by  injecting  ptomains  into  animals. 

Ptomains  are  chiefly  the  cause  of  disease  when  they  are  taken 
in  with  food  in  which  they  have  been  produced  by  bacterial 
decomposition.  Besides  this  food  poisoning,  it  is  also  possible 
that  ptomains  may  be  formed  by  putrefaction  within  the  gastro- 
intestinal tract.  Another  possible  source  of  ptomains  is  fur- 
nished by  decomposing  tissues  in  gangrene.  It  is  doubtful  if 
ptomains  are  produced  in  sufficient  quantities  by  pathogenic 
bacteria  infecting  living  tissue  to  be  of  any  importance.  Food- 
poisoning  is  by  no  means  uncommon,  but  it  is  not  always  due 
to  ptomains ;  it  may  be  the  result  of  poisonous  materials  con- 
tained abnormally  in  the  food,  that  are  not  ptomains,  e.  g.,  ergot- 
ism ;  or  it  may  be  due  to  an  infection  of  the  animal  from  which 
the  meat  came  with  pathogenic  organisms,  particularly  the  B. 
enteritidis  of  Gaertner  and  other  bacteria  related  to  the  colon- 
typhoid  group  ;  or  in  other  ways  food  ordinarily  wholesome  may 
become  poisonous.  The  commonest  sources  of  ptomam  poison- 
ing are  imperfectly  preserved  canned  meats,  sausages,  decom- 
posing fish,  cheese,  ice-cream,  and  milk. l 

Chemical  Composition  of  Ptomains. — To  indicate  the 
composition  and  nature  of  ptomains  a  few  of  the  more  impor- 
tant ones  may  be  described.  As  illustrative  of  the  simpler 
forms  may  be  mentioned  : 

Methyl  amine,  CH3  —  NH2. 

Di-methyl  amine,  CH3  —  NH  —  CH3. 

Tri-methyl  amine,  CHS  —  N  —  CH3. 

CH3 

These    bodies,  which    are   commonly   found    in   decomposing 

1  All  these  matters  are  discussed  at  length  by  Vaughan  and  Novy,  to  whose 
book  the  reader  is  referred. 


118   CHEMISTRY  OF  BACTERIA  AND  THEIR  PRODUCTS 

proteids,  are  but  very  slightly  toxic,  and  of  little  pathological 
importance. 

When  we  examine  the  structural  formulae  of  some  of  the 
larger  ptotnam  molecules  and  compare  them  with  the  formulae 
of  the  amino-acids  that  form  the  proteid  molecule,  the  relation 
is  apparent,  e.  g.,  compare  iso-amylamin  with  leucin. 


-  CH2  —  CH2  -  NH3  >CH  -  CH2—  CH  -  NH2 

CH/  \nnnw 

(iso-amylamin)  (leucinj  *-/<JUii. 

Putresdn,  C4H12N2,  structural  formula, 

NH2  —  CH2  —  CH2  —  CH2  —  CH2  —  NH2, 
and  cadaverin,  C5H14N2,  structural  formula, 

NH2  —  CH2  —  CH2  —  CH2  —  CH2  —  CH2  -  NH2, 

are  of  interest  because  they  have  been  found  in  the  intestinal 
contents,  arising  from  putrefaction  of  proteids,  and  also  are 
sometimes  present  in  the  urine  in  cystinuria.1  They  are  closely 
related  to  the  diamino-acids,  lysin  and  ornithin.  They  are  but 
slightly  toxic,  although  capable  of  causing  local  necrosis  when 
injected  subcutaneously.  (See  further  discussion  in  Chapter  xix.) 
The  Cholin  Group.  —  Another  group  of  ptornams,  includ- 
ing cholin  and  closely  related  substances,  is  also  of  interest. 
These  ptomams  are  : 

Cholin,  CH2OH  —  CH2—  N(CH,)8  —  OH 

Neurin,  CH2=  CH  —  N(CH3)3  —  OH 

Muscarin,8         CH  (OH)2—  CH2—  N(CH3)3  —  OH 
Betain  COOH  —  CH2—  N(CH3)3  —  OH 

The  first  point  of  importance  is  that  cholin  is  present  in  every 
cell  normally,  forming  the  nitrogenous  portion  of  the  lecithin 
molecule.  Its  source  in  putrefaction  of  tissues  is,  therefore, 
plain.  Furthermore,  it  seems  to  be  liberated  during  life  when- 
ever nervous  tissue,  which  is  rich  in  lecithin,  is  broken  down  in 
any  considerable  amount.  Mott  and  Halliburton3  claim  that 
it  can  be  found  in  both  the  blood  and  the  cerebrospinal  fluid 
of  man  and  animals  suffering  with  severe  nervous  lesions.4 

1  UdranszkyandBaumann,  Zeit  physiol.  Chem.,1889(13),562;  1889(15),  77. 

2  Other  structural  formulae  have  been  given  for  muscarin,  e.g., 

CH2(OH)  —  CHOH  —  N(CH3)3OH. 

3  See  Halliburton,  "  Chemistry  of  Muscle  and  Nerve,"  Philadelphia,  1904. 
*  Coriat  (Amer.  Jour,  of  Physiol.,  1904  (12),  353)  has  studied  the  conditions 

under  which  cholin  may  be  produced  from  lecithin.  Putrefaction  of  lecithin 
or  lecithin-  rich  tissues  liberates  cholin,  as  also  does  autolysis  of  brain  tissue  ; 
neither  pepsin  nor  trypsin,  however,  splits  it  from  the  lecithin.  In  brain  tissue, 
therefore,  there  seems  to  be  an  enzyme  different  from  trypsin,  which  splits 
cholin  out  of  the  lecithin  molecule. 


PTO  MAINS  119 

Cholin  itself  is  somewhat  toxic,  but  the  closely  related  body, 
neurin,  into  which  it  may  be  transformed,  is  highly  poisonous, 
which  makes  cholin  an  important  indirect  source  of  intoxication. 
It  is  possible,  for  example,  that  lecithin  taken  in  the  food  splits 
off  cholin  in  the  gastro-intestinal  tract,  and  this  being  converted 
into  neurin  gives  rise  to  intoxication  which  may  be  ascribed  to 
food  intoxication.  Likewise  it  has  been  suggested  that  the 
intoxication  of  fatigue  may  be  due,  at  least  in  part,  to  cholin  and 
neurin  produced  from  lecithin  decomposed  during  the  period  of 
cellular  activity.  The  close  structural  relation  to  cholin  and 
neurin,  of  the  mushroom  poison,  muscarin,  which  produces 
physiological  effects  very  similar  to  those  of  neurin,  indicates 
the  close  relationship  of  the  putrefactive  ptomams  and  the  vege- 
table alkaloids.  Indeed  a  muscarin  apparently  identical  with 
that  of  the  mushroom  has  been  found  in  decomposing  flesh,  and 
neurin,  presumably  derived  from  lecithin,  may  be  found  in 
human  urine.1  Betain,  the  fourth  member  of  the  group,  which 
has  but  slight  toxicity,  is  particularly  well  known  as  a  constit- 
uent of  plant  tissues ;  possibly  betain  or  other  basic  bodies  may 
occur  substituted  for  cholin  in  certain  varieties  of  lecithin  (Lipp- 
mann). 

Both  neurin  and  muscarin  are  extremely  poisonous  and  quite 
similar  in  their  effects.  Subcutaneous  injection  of  but  1  to  3  mg. 
of  muscarin  in  man  produces  salivation,  rapid  pulse,  reddening  of 
the  face,  weakness,  depression,  profuse  sweating,  vomiting,  and 
diarrhoea.  Neurin,  likewise,  causes  salivation,  lachrymation, 
vomiting,  and  diarrhoea.  In  fatal  poisoning  respiration  ceases 
before  the  heart  stops.  Both  poisons  resemble  physostigmine 
in  their  stimulation  of  secretion  and  are  equally  well  counter- 
acted by  atropin.  The  toxicity  of  these  substances  is  so  great 
that  not  a  large  amount  would  need  to  be  formed  by  oxidation 
of  cholin  to  produce  severe  symptoms,  although  it  is  not  known 
that  this  actually  occurs  in  the  body.  When  introduced  by 
mouth,  the  lethal  dose  of  neurin  is  ten  times  as  great  as  when 
injected  subcutaneously,  indicating  that  chemical  changes  in  the 
gastro-intestinal  tract  offer  some  protection  against  intoxica- 
tion by  these  substances  when  taken  in  tainted  food.  Cholin, 
although  by  no  means  so  poisonous  as  neurin,  has  a  similar 
action  when  administered  in  sufficiently  large  doses.  Accord- 
ing to  Brieger,  it  is  about  one-tenth  to  one-twentieth  as  toxic  as 
neurin.2  Cholin  seems  to  be  rapidly  destroyed  in  the  body, 

1  Kutscher  and  Lohmann,  Zeit.  physiol.  Chem.,  1906  (48),  1. 

2  Halliburton,  "Chem.  of  Muscle  and  Nerve,"  1904,  p.  119,  states  that  cholin 
produces  a  fall  in  blood  pressure  by  dilating  the  peripheral  vessels,  whereas 


120   CHEMISTRY  OF  BACTERIA  AND   THEIR  PRODUCTS 

not  appearing  in  the  urine1  but  forming  formic  acid  and 
perhaps  glyoxylic  acid.  Donath2  found  that  cholin  injected 
directly  into  the  cortex  or  under  the  dura  is  extremely  toxic, 
causing  severe  tonic  and  clonic  convulsions,  and  believes  that 
cholin  may  be  responsible  for  epileptic  convulsions,  since  he  has 
found  that  cholin  is  present  in  the  cerebrospinal  fluid  of  epilep- 
tics. He  corroborated  the  work  of  Mott  and  Halliburton, 
finding  quantities  large  enough  to  detect  (0.02  to  0.05  per 
cent.)  in  the  cerebrospinal  fluid  of  patients  with  dementia 
paralytica,  tabes  dorsalis,  cerebral  syphilis,  brain  abscess,  and 
other  conditions  associated  with  destruction  of  nervous  tissue, 
but  in  functional  disorders  he  found  it  seldom  or  never.  In 
genuine  syphilitic  and  Jacksonian  epilepsy  cholin  was  found  in 
19  of  22  cases.  Cholin  may  be  found  in  normal  cerebrospinal 
fluid,  but  in  extremely  minute  quantities.  When  large  nerves 
are  cut,  cholin  appears  in  the  blood,  derived  from  the  lecithin  of 
the  disintegrating  nerve  fibers,  and  is  most  abundant  at  the 
time  the  Marchi  reaction  is  most  prominent  in  the  nerves. 

TOXINS 

Certain  bacteria  produce  soluble  poisons  by  synthetic  proc- 
esses, which  poisons  are  secreted  into  the  surrounding  medium 
and  which  represent  the  chief  poisonous  products  of  the  bacteria, 
being  capable  of  causing  most  or  all  of  the  symptoms  attributed 
to  infection  by  the  specific  bacteria  that  have  manufactured 
them.  To  this  class  of  soluble  poisons  the  term  toxin  has  now 
become  limited  (for  reasons  that  will  be  mentioned  below), 
including  not  only  toxins  of  bacterial  origin,  but  also  poisons 
of  similar  nature  produced  by  animals  (snake  venoms,  eel  serum, 
etc.)  and  by  plants  (ricin,  abrin,  crotin).  The  bacteria  secreting 
true  toxins  are  B.  diphiherwe,  B.  tetani,  B.  pyocyaneus,  and 
_B.  botulinus  (not  including  bacteria  producing  hemolytic  sub- 
stances resembling  toxins).  It  will  be  seen  that  the  term  toxin 
has  been  greatly  narrowed  since  the  time  when  all  ptomains 
and  other  poisonous  bacterial  products  were  called  toxins,  until 

neurin  constricts  the  peripheral  vessels ;  he  uses  this  difference  in  physiological 
effect  as  a  means  of  distinguishing  the  two  substances.  Injected  into  animals, 
cholin  causes  a  considerable  but  transient  decrease  in  the  number  of  leucocytes 
in  the  blood,  followed  later  by  an  increase  (Werner  and  Lichtenberg,  Deut. 
med.  Woch.,  1906  (32),  22). 

1  v.  Hoesslin,  Hofmeister's  Beitr.,  1906  (8),  271. 

2Zeit.  f.  physiol.  Chem.,  1903  (39),  526;  also  see  Med.  News,  1905  (86), 
107,  for  literature  and  methods  of  analysis.  Full  review  of  subjects  of  cholin 
and  neurin  in  these  relations  by  Halliburton,  Ergeb.  der  Physiol.,  1904  (4), 


TOXINS  121 

now  it  has  come  to  include  the  specific  poisons  of  but  four  of 
the  great  group  of  pathogenic  bacteria.1 

Chemical  Properties  of  Toxins. — The  chemical  nature 
of  the  toxins  is  entirely  unknown.  By  various  precipitation 
methods  they  may  be  carried  down,  but  included  with  them  are 
masses  of  impurities,  chiefly  proteids.  It  is  quite  certain  that 
toxins  are  not  proteids,  since  very  active  toxins  have  been 
obtained  by  purification  processes  that  did  not  give  the  proteid 
reactions.  The  old  name  of  "  toxalbumin"  is,  therefore, 
incorrect.  Oppenheimer2  says  of  the  toxins  that  "  we  must  be 
contented  to  assume  that  they  are  large  molecular  complexes, 
probably  related  to  the  proteids,  corresponding  to  them  in 
certain  properties,  but  standing  even  nearer  to  the  equally 
mysterious  enzymes  with  whose  properties  they  show  the  most 
extended  analogies  both  in  their  reactions  and  in  their  activities.77 
These  similarities  between  toxins  and  enzymes  are  very  striking, 
and  in  discussing  the  nature  of  the  enzymes  we  have  mentioned 
the  reasons  for  considering  them  related  to  the  toxins ;  we  may 
now  take  up  the  other  side  of  the  question  and  consider  the 
relation  of  the  toxins  to  the  enzymes. 

Resemblance  to  Enzymes. — First  of  all  we  meet  the  same 
difficulty  in  isolating  toxins  that  we  do  in  isolating  enzymes. 
"  A  pure  toxin  is  as  unknown  as  a  pure  enzyme  "  (Oppenheimer). 
At  first  both  were  believed  to  be  proteids ;  now  both  are  con- 
sidered by  many  not  to  be  proteids,  but  molecular  complexes  of 
nearly  equally  great  dimensions.  That  toxins,  like  enzymes,  are 
colloids,  has  been  abundantly  demonstrated.3  Both  pass  through 
porcelain  filters,  but  both  lose  much  of  their  strength  in  the 
process,  and  they  are  almost  entirely  held  back  by  dialyzing 
membranes.  Neither  will  withstand  boiling,  and  most  forms 
are  destroyed  at  80°  instantly  or  in  a  very  short  time ;  on  the 
whole,  however,  toxins  are  more  susceptible  to  heat,  as  well  as 
to  most  other  injurious  agencies.  Both  stand  dry  heat  over 
100°,  and  extremely  low  temperature,  without  much  injury. 
Left  standing  in  solution  for  some  time  they  gradually  lose  their 
specific  properties,  and  in  each  case  this  seems  to  be  due  to  an 
alteration  in  the  portion  of  the  molecule  that  produces  the 

1  In  addition  to  the  ordinary  toxins,  Ehrlich  recognizes  other  poisons  secreted 
by  the  diphtheria  bacillus  which  have  a  less  specific  and  less  actively  poisonous 
action;  and  called  toxones.     (This  conception  is  contested  by  Arrhenius  and 
Madsen).     The  toxins  also  vary  in  their  affinity  for  antitoxin,  and  on  this 
basis  have  been  divided  into  proto-,  deutero-,  and  tritotoxin.     These  refinements 
of  division  are  not  necessary  for  our  consideration  of  the  chemical  features  of 
immunity. 

2  Kolle  and  Wassermann's  Handbuch,  1903  (1),  351. 

3  See  Zangger,  Cent.  f.  Bakt.  (ref.),  1905  (36),  239. 


122   CHEMISTRY  OF  BACTERIA  AND  THEIR  PRODUCTS 

destructive  effects  (toxophore  or  zymophore  group),  while  the 
portion  of  the  molecule  that  unites  with  the  substance  that  is  to 
be  attacked  (haptophore  group)  remains  uninjured,  the  toxin 
becoming  a  toxoid,  the  enzyme  a  fermentoid.  Enzymes  as  well 
as  toxins  are  poisonous  when  injected  into  animals,  and  the 
animals  react  to  each  by  producing  substances  (anti-bodies)  that 
render  each  inert,  probably  in  the  same  way.  On  the  other 
hand,  enzymes  and  toxins  seem  to  produce  their  effects  according 
to  different  laws : — A  small  amount  of  enzyme  can  in  course 
of  time  produce  an  almost  indefinite  amount  of  effect,  whereas 
toxins  act  more  nearly  quantitatively.  It  seems  as  if  the 
enzyme  were  bound  to  the  body  upon  which  it  acts,  as  is  the 
toxin,  but  that  after  it  has  destroyed  this  body  it  is  set  free  in  a 
still  active  form,  ready  to  accomplish  further  work,  whereas  the 
toxin  is  either  not  set  free,  or  it  becomes  inactive  after  it  has 
once  been  combined. 

Agencies  Destroying  Toxins. — Toxins  are  very  susceptible 
to  light,  direct  sunlight  soon  destroying  the  power  of  toxin 
solutions. l  Oxygen,  even  dilute  as  in  air,  is  harmful ;  and  all 
oxidizing  agents,  including  oxidizing  enzymes,  destroy  them 
quickly.  Like  enzymes,  they  withstand  such  antiseptics  as 
chloroform,  toluol,  etc.,  and  are  precipitated  by  the  heavy 
metals.  Some  agencies  seem  to  attack  only  the  toxophore  portion 
of  the  molecule,  e.  <?.,  iodin,  carbon  disulphid  (Ehrlich). 

Introduced  into  the  gastro-intestinal  tract,  most  bacterial 
toxins  are  not  absorbed  (botulinus  toxin  excepted),  cause  no 
symptoms,  and  do  not  reappear  in  the  feces  ;  they  are  therefore 
destroyed  by  the  contents  of  the  tract,  pepsin,  pancreatic  juice, 
and  bile  all  being  capable  of  destroying  toxins.2  They  may, 
however,  when  injected  subcutaneously,  circulate  unimpaired  in 
the  blood  of  non-susceptible  animals,  gradually  disappearing, 
more  through  slow  processes  of  destruction  than  by  elimination. 
When  injected  into  susceptible  animals,  they  soon  disappear  from 
the  blood,  being  fixed  in  the^organs  that  they  attack. 

Differences  from  Ptomains. — While  ptomai'ns  are  formed 
by  cleavage  processes  from  the  medium  upon  which  the  bacteria 
grow,  and  the  same  ptomai'ns  can  be  produced  by  several  different 
kinds  of  bacteria,  the  toxins  are  synthetic  products  of  absolutely 

1  Fluorescent  substances  have  a  destructive  effect  upon  toxins,  even  in  the 
animal  body,  according  to  lodlbauer  and  v.  Tappeiner,  Deut.  Arch.  klin.  Med., 
1905  (85),  399. 

8  Baldwin  and  Levene  (Jour.  Med.  Kesearch,  1901  (6),  120)  found  that  diph- 
theria and  tetanus  toxin  are  both  destroyed,  apparently  through  digestion,  by 
pepsin,  trypsin  and  papain  acting  for  several  days.  Keview  of  Literature  by 
Lust,  Hofmeister's  Beitr.,  1904  (6),  132. 


TOXINS  123 

specific  nature.  That  they  are  produced  by  synthesis  can  be 
shown  by  growing  the  bacteria  on  Uschinsky's  or  similar  media, 
which  contain  no  proteids,  carbohydrates,  or  fats,  but  merely 
simple  organic  and  inorganic  salts  of  known  composition  ;  on 
these  media  the  bacteria  produce  their  specific  toxins,  which 
must,  therefore,  be  synthesized.1  Furthermore,  diphtheria 
toxin  is  essentially  the  same  no  matter  on  what  sort  of  medium 
it  is  grown,  whereas  ptomai'ns  vary  with  the  nature  of  the 
substance  from  which  they  are  produced.  Toxins  are  true 
secretions  of  bacterial  cells,  just  as  trypsin  is  of  pancreatic  cells, 
or  thyroiodin  of  thyroid  cells.  Anti-bodies  can  be  produced 
against  toxins,  but  not  against  ptomains. 

Ehrlich's  Conception  of  the  Nature  of  Toxins. — 
Chemical  studies  of  toxins  being  impossible,  we  have  been 
obliged  to  study  them  through  their  physiological  effects,  just 
as  we  have  obtained  information  concerning  enzymes  through 
their  specific  actions.  In  this  way  Ehrlich  has  obtained  well- 
crystallized  ideas  concerning  the  structure  of  toxins,  as  well  as 
the  manner  in  which  they  act,  which  may  be  briefly  summarized 
as  follows  :  Each  toxin  molecule  consists  of  a  large  number  of 
organic  complexes  grouped,  as  in  other  organic  compounds,  as 
side-chains  about  a  central  chain  or  radical.  One  or  more  of 
these  complexes  has  a  chemical  affinity  for  certain  chemical  con- 
stituents of  the  tissues  of  susceptible  animals,  with  which  the  toxin 
molecule  unites ;  this  binding  group  is  called  the  haptophore 
(meaning  "  bearing  a  bond  "  ).  Another  side-chain  or  group  of 
side-chains  exerts  the  injurious  effects  upon  the  tissue  to  which 
the  molecule  has  been  bound  by  the  haptophore,  and  cannot  pro- 
duce these  injurious  effects  unless  it  has  been  so  bound.  This 
injury- working  group  is  called  the  toxophore.  An  animal  is 
susceptible  to  a  toxin  only  when  its  cells  contain  substances 
which  possess  a  chemical  affinity  for  the  haptophore  groups  of 
the  toxin,  and  also  substances  which  can  be  harmfully  influenced 
by  the  toxophore  groups.  Tetanus  toxin,  for  example,  owes  its 
effects  to  the  fact  that  nervous  tissues  contain  chemical  sub- 
stances having  a  strong  affinity  for  the  haptophore  group  of 
tetanus  toxin,  and  also  substances  that  can  be  attacked  with 
serious  results  by  the  toxophore  group  of  the  toxin.  The  nature 
of  the  changes  brought  about  by  the  toxophore  groups  of  toxins 
is  not  understood ;  there  are  many  resemblances  to  the  action 
of  enzymes,  but  the  analogy  is  by  no  means  complete.  We  find 
perhaps  the  closest  analogy  to  the  enzymes  in  the  toxic  sub- 
stances that  destroy  red  corpuscles  and  bacteria  (hemolysins, 
1  Zinno  could  not  confirm  this  observation  (Cent.  f.  Bakt.,  1902  (31,  Abt.  1),  42). 


124   CHEMISTRY  OF  BACTERIA  AND  THEIR  PRODUCTS 

bacteriolysins),  which  will  be  considered  in  another  place.  The 
immunity  against  toxins  and  enzymes  seems  to  be  produced  by 
identical  processes,  which  consist  in  an  overproduction  of  the 
cellular  constituents  (receptors)  which  bind  the  haptophore 
groups  to  the  cells,  these  excessive  receptors  being  secreted  into 
the  blood,  where  they  combine  with  the  toxin  or  enzyme  so 
that  it  cannot  enter  into  combination  with  the  cells. 

Immune  substances  cannot  be  produced  against  ptoma'ins,  or 
for  that  matter  against  the  vegetable  alkaloids,  or  against 
any  chemical  bodies  of  known  constitution.  Another  difference 
between  the  action  of  toxins  and  simpler  chemical  poisons  is, 
that  while  with  the  latter  the  effects  are  produced  in  a  very 
short  time  after  injection,  there  is  a  latent  period  of  several  hours 
before  symptoms  appear  after  injecting  toxins.  What  occurs 
during  this  latent  period  is  not  fully  known,  but  that  there  is  a 
latent  period  suggests  a  resemblance  to  enzyme  action.  An 
alkaloidal  or  other  chemical  poison  enters  the  cell,  and  its  harm 
is  done  at  once.  A  toxin  combines  with  the  cell,  and  then,  if 
it  produces  its  effects  by  an  enzymatic  alteration  of  the  cellular 
structure,  some  time  must  elapse  before  the  changes  are  great 
enough  to  cause  the  appearance  of  symptoms. 

ENDOTOXINS 

By  far  the  greater  number  of  pathogenic  bacteria  do  not  secrete 
their  poisons  as  toxins  into  the  surrounding  medium,  although 
they  manifestly  cause  disease  by  poisoning  their  host.  Among 
them  are  such  organisms  as  the  typhoid  bacillus,  pneumococcus, 
the  pus  cocci,  cholera  vibrios,  and  many  others.  If  cultures 
of  these  organisms  are  filtered,  the  filtrate  will  be  found  to  be 
but  slightly  toxic  (except  for  the  hemolytic  poisons),  although 
the  bodies  of  the  bacteria  after  they  have  been  killed  by  chloro- 
form or  other  antiseptics  are  highly  poisonous  if  injected  into 
an  animal.  These  bacteria,  then,  produce  poisons  which  do 
not  escape  from  the  cells  into  the  culture-medium,  but  are 
firmly  held  within  them.  By  using  various  means  these  intra- 
cellular  toxins,  or  endotoxins,  can  be  obtained  independent  of 
the  bacterial  cells.  One  of  these  is  to  grind  up  the  cells,  which 
can  be  particularly  well  done  if  they  are  first  made  brittle  by 
freezing  at  the  temperature  of  liquid  air  (MacFadyen's  method). 
By  very  great  pressure  in  the  Buchner  press  the  cellular  con- 
tents can  be  expressed.  They  may  also  be  obtained  by  letting 
the  bacteria  autolyze  themselves  for  a  short  time  in  non-nutrient 
fluids  (Conradi,1  et  al.).  Endotoxins  obtained  in  this  way  are 

1  LOG  dt. 


ENDOTOXINS  125 

soluble  and  highly  poisonous,  and  it  is  undoubtedly  through 
their  action  that  the  characteristic  diseases  are  produced  by  the 
bacteria  that  contain  them.  Presumably  the  endotoxins  are 
liberated  in  the  body  either  by  autolysis,  or,  more  probably,  by 
heterolysis  by  the  enzymes  of  the  body  cells  and  fluids. 

Endotoxins  differ  from  the  true  toxins,  however,  in  one 
important  respect :  namely,  no  antitoxin  has  been  obtained  for 
endotoxins  by  immunization  of  animals.1  Animals  immunized 
against  endotoxins  develop  in  their  serum  substances  that  are 
bactericidal  and  agglutinative  to  the  bacteria  from  which  the 
poisons  are  derived,  but  the  serum  will  not  neutralize  the  endo- 
toxins,2 As  a  result,  we  are  unable  to  perform  experiments 
indicating  whether  endotoxins  have  the  same  structure  as  the  true 
toxins,  i.  e.}  a  haptophore  and  a  toxophore  group,  but  presumably 
their  nature  is  different  in  some  essential  particular.  The  chemi- 
cal nature  of  the  endotoxins  is  also  unknown,  for  they  are  always 
obtained  mixed  with  the  other  constituents  of  the  bacteria. 

Since  far  more  bacterial  diseases  are  brought  about  by  endo- 
toxins than  by  true  toxins,  the  failure  to  secure  antitoxins  for 
these  substances  has  been  a  great  check  in  the  progress  of  serum 
therapy,  and  the  problem  of  the  endotoxins  is  one  of  the  most 
important  in  the  entire  field  of  immunity. 

POISONOUS  BACTERIAL  PROTEIDS 

If  we  filter  a  bouillon  culture  of  diphtheria  bacilli  through 
porcelain,  wash  thoroughly  the  bacteria  remaining  with  salt  solu- 
tion, and  collect  them  thus  freed  from  their  secretion  products, 
it  will  be  found  that  extracts  of  the  bacterial  substance  or  the 
bodies  of  the  killed  bacteria  themselves  are  quite  free  from  the 
typical  toxin.  This  indicates  that  the  toxin  is  eliminated  from 
the  bacteria  as  fast  as  it  is  formed,  and  no  considerable  quantity 
is  retained  within  the  cell.  The  bacterial  substance,  however, 
or  proteids  isolated  from  it,  is  found  to  produce  severe  local 
changes  when  injected  into  the  bodies  of  animals,  necrosis  and 
a  strong  inflammatory  reaction  with  pus-formation  being  the 
chief  features.  This  local  effect  is  not  a  specific  property  of  the 
diphtheria  bacillus,  for  other  bacterial  proteids,  including  proteids 
from  non-pathogenic  bacteria,  will  produce  the  same  changes ; 
indeed,  many  proteids  that  are  derived  from  vegetable  and  ani- 
mal sources  have  equally  marked  pyogenic  properties.  All 
foreign  proteids  when  introduced  into  the  circulation  of  animals 

1  Positive  results  are  claimed  by  Besredka,  (Ann.  Inst.  Pasteur,  1906  (20), 
304),  and  a  few  others;  see  Kraus,  Wien.  klin.  Woch.,  1906  (19),  No.  22. 

2  See  resume*  by  F.  Schmidt,  Zeit.  f.  Infektionskr.  der  Haustiere,  1906  (1), 
238,  and  Hahn,  Munch,  med.  Woch.,  1906  (53),  No.  23. 


126   CHEMISTRY  OF  BACTERIA  AND   THEIR  PRODUCTS 

are  more  or  less  toxic,  and  the  toxic  effects  of  the  bacterial  pro- 
teids  are,  for  the  most  part,  neither  specific  nor  particularly 
striking.  There  are  a  few  pathogenic  organisms,  however, 
which  seem  to  produce  neither  true  toxins  nor  endotoxins,  not- 
ably the  tubercle  bacillus  and  the  anthrax  bacillus,  and  with 
these  there  may  be  a  relation  between  their  proteid  constituents 
and  their  specific  effects.1 

Numerous  proteid  substances  have  been  extracted  from  bac- 
terial cells,  particularly  nucleoproteids,  but  also  proteids  resem- 
bling albumins,  nucleo-albumin,  and  globulins.  In  all  probability 
the  chief  proteids  of  the  bacterial  cell  are  nuclein  compounds, 
which  is  indicated  both  by  their  nuclear  staining  and  by  the 
analyses  of  Iwanoff ; 2  and  many  of  the  nucleoproteids,  both  of 
bacterial  and  non-bacterial  origin,  cause  considerable  local 
inflammatory  reaction  when  injected  into  animals.  Tiberti3 
claims  that  vaccination  with  non-lethal  doses  of  the  nucleo- 
proteids of  anthrax  bacilli  will  protect  animals  against  inocu- 
lations of  virulent  anthrax  bacilli.  Some  of  the  earlier 
observations  on  the  toxicity  of  bacterial  proteids  were  erroneous 
because  impure  proteids,  containing  toxins,  endotoxins,  and 
ptomams  were  used. 

Vaughan  and  his  students  have  been  able  to  split  off  from 
the  bodies  of  various  pathogenic  bacteria  toxic  materials  which 
are  stated  to  resemble  in  some  respects  the  protamins, 4  although 
they  do  not  all  give  a  satisfactory  biuret  test.  These  toxic 
materials  are  evidently  quite  different  from  either  the  true  solu- 
ble toxins  or  the  endotoxins,  since  they  resist  heating  for  ten 
minutes,  at  110°  in  the  autoclave  with  1  per  cent,  sulphuric  acid, 
this  being  the  method  used  for  securing  the  substance,  which  is 
precipitated  out  by  alcohol.  Since  the  sarcinse  and  B.  prodigio- 
sus  also  yield  similar  toxic  products,  they  cannot  be  considered 
as  the  specific  toxic  substances  of  the  pathogenic  bacteria.  With 
some  bacteria  the  splitting  process  with  sulphuric  acid  separates 
completely  the  toxic  from  the  non-toxic  insoluble  bacterial  sub- 
stance,5 e.  g.y  B.  coli  communis ;  with  others  a  toxic  portion 
remains  insoluble.  The  colon  bacillus  proteid  gives  all  the 
proteid  reactions,  is  synthesized  on  Uschinsky's  medium,  and 
does  not  yield  a  reducing  carbohydrate.  From  B.  typhosus 

1  Baldwin  and  Levene  (loc.  cit.)  found  that  the  active  constituent  of  tuber- 
culin was  destroyed  or  digested  by  trypsin  and  not  by  pepsin,  indicating  that 
it  was  probably  a  nucleoproteid. 

2  Hofmeister's  Beitr.,  1902  (1),  524.  3  Cent.  f.  Bakt.,  1906  (40),  742. 

*  Jour.  Amer.  Med.  Assoc.,  1903  (40),  838;  1904  (43),  643;  see  also  Boston- 
Med.  and  Surg.  Jour.,  Aug.  30  et  seq.,  1906. 

5  Wheeler,  Jour.  Amer.  Med.  Assoc.,  1905  (44),  1271. 


BACTERIAL  PIGMENTS  127 

about  10  per  cent,  by  weight  of  proteid  can  be  split  off  by 
dilute  acid,  of  which  at  least  a  part  seems  to  be  a  phosphorized 
glycoproteid.1  Poisonous  substances  have  also  been  obtained 
from  B.  diphtherias,  B.  anthracis,  and  B.  pyocyaneus.  They 
produce  death  without  the  usual  latent  period  observed  with 
toxins,  but  are  very  toxic,  a  few  (10-20)  milligrams  of  colon 
bacillus  poison  killing  guinea-pigs  in  less  than  ten  minutes.2  A 
certain  degree  of  immunity  can  be  obtained  against  them.3 
Their  relation  to  endotoxins  has  yet  to  be  determined.4  It  is 
possible  that  they  are  toxic  bodies  derived  from  the  endotoxins 
through  alterations  produced  during  the  process  of  isolation, 
bearing  the  same  relation  to  endotoxins  that  acid  and  alkali 
albuminate  do  to  the  original  proteids — modified  or  "  denaturi- 
erte"  proteids  (Wolff5). 

BACTERIAL  PIGMENTS6 

The  formation  of  pigment  by  bacteria  seems  to  be,  for  the 
most  part,  an  adventitious,  unessential  property.  There  are  a 
few  bacteria  which  possess  pigments  of  the  nature  of  chloro- 
phyll, or  allied  to  it,  and  this  pigment  is  undoubtedly  of  great 
importance  in  the  life  processes  of  these  particular  forms.  Other 
varieties  of  pigment-forming  bacteria,  of  which  but  very  few 
are  pathogenic  (Bacillus  pyocyaneus,  B.  proteus  fluorescens,  8. 
pyogenes  aureus  and  citreus,  M.  cereus  flavus),  seem  to  produce 
pigment  as  a  waste  product  which  is  excreted  from  the  cell  as 
fast  as  formed.  Generally  the  pigments  are  produced  in  a 
colorless  form  (leuco-base)  which  is  oxidized  by  the  air  into  the 
pigment,  e.  g.,  in  pyocyaneus  infections  the  soiled  dressings  are 
most  colored  about  the  portions  most  exposed  to  air.  Since 
pigment-forming  bacteria  produce  pigments  only  under  certain 
conditions,  and  can  grow  abundantly  without  producing  any 
pigment,  it  is  evident  that  the  pigment  formation  is  no  very 
essential  part  of  their  metabolism.  It  is  possible  to  modify 
pigment  production  almost  at  will,  and  even  to  develop  races 
of  bacteria  that  do  not  produce  pigment  at  all,  from  races  that 
ordinarily  are  pigment-producers. 

Of  numerous  classifications  of  pigment-forming  bacteria,  all 

1  Ibid.,  1904  (42),  1000. 

2  Ibid.,  1905  (44),  1340  ;  American  Medicine,  1905  (10),  145. 
3 Vaughan  (Jr.),  Jour,  of  Med.  Kesearch,  1905  (14),  67. 

4  An  important  argument  against  the  specific  nature  of  these  poisons  is  the 
close  resemblance  to  poisons  obtained  from  liver  cells,  egg-albumen,  etc.,  by 
similar  methods.      Vaughan  considers  that  every  protein  molecule,  whether 
bacterial  or  not,  has  a  poisonous  group,  which  contains  the  benzene  ring. 

5  Cent.  f.  Bakt.  (1  Abt.),  1904  (37),  687. 

6  For  complete  bibliography  and  re"sum6  see  Sullivan,  Jour.  Med.  Kesearch, 
1905  (14),  109. 


128    CHEMISTRY  OF  BACTERIA  AND   THEIR  PRODUCTS 

faulty  because  of  our  slight  knowledge  of  the  chemistry  of  the 
process,  that  of  Migula  seems  the  best ;  it  is  based  on  the  solu- 
bility of  the  pigments  formed,  as  follows  : 

(1)  Pigments  Soluble  in  Water. — This  includes  the  pig- 
ments of  all  fluorescent  bacteria,  as  well  as  those  giving  a  red 
or  brown  color  to  gelatin  media.     Most  important  among  these 
is  Bacillus  pyocyaneus,  whose  pigments  have  been  considerably 
studied.     There   seem    to    be    two  pigments,  one,  pyocyanin, 
characteristic  for  this    organism ;    and    a    fluorescent    pigment 
which  numerous  other  organisms  also  produce.      Pyocyanin  has 
been  analyzed  by  L/edderhose,  who  found  it  to  be  a  ptomam- 
like  body,  a  derivative  of  the  aromatic  series,  probably  related 
to  the  anthracenes.    It  can  be  reduced  to  a  colorless  letico-base, 
in  which  form  it  is  probably  produced  by  the  bacteria,  and  then 
is  oxidized  in  the  air  into  the  pigment.      Its  composition  is 
C14HUN2O  (the  sulphur-containing  pyocyanin  which  has  been 
described  is  probably    impure).     The   fluorescent   pigment    is 
insoluble  in  alcohol  and  chloroform,  and  can  thus  be  separated 
from  pyocyanin,  which   is  soluble   in    chloroform.     Although 
related  to  the  ptomai'ns,  pyocyanin  seems  to  be  altogether  non- 
poisonous  to  animals. 

Jordan1  and  Sullivan2  have  studied  the  conditions  under 
which  pigments  are  formed,  and  found  that  pyocyanin  can  be  pro- 
duced in  proteid-free  media,  and  without  the  presence  of  either 
phosphates  or  sulphates ;  but  both  sulphur  and  phosphorus 
must  be  present  to  produce  the  fluorescent  pigment.  As  pig- 
ments can  be  produced  on  media  containing  ammonium  salts  of 
succinic,  lactic,  or  aspartic  acid,  or  asparagin,  they  are  evidently 
formed  synthetically,  and  not  by  cleavage  of  the  media. 

(2)  Pigments  Soluble  in  Alcohol  and  Insoluble  in  Water.— 
The  most  important  bacteria  of  this  group  are  the  Staphylo- 
coccus  pyogenesaureus  and  citreus.     Their  pigment  is  of  a  fatty 
nature,  a  lipochrome,  which  lies  among  the  bacteria  in  the  form 
of  dendritic  crystals.     Being  a  fat,  it  can  be  saponified,  and 
when  decomposed  it  gives  the  acrolein  reactions  and  odor,  from 
the  breaking  down  of  the  glycerin  of  the  fat  molecule.     Acted 
upon  by  strong  sulphuric  acid,  the  yellow  pigment  changes  into 
blue  granules  and   crystals    (Jipocyanin  reaction).     The    lipo- 
chromes  are  soluble  in  the  usual  fat  solvents,  and  form  fat  spots 
on  paper. 

(3)  Pigments  Insoluble  in  Water  and  in  Alcohol. — The 
pigment  of  Micrococcus  cereus  flavus  belongs  to  this  class ;  its 
nature  is  quite  unknown. 

Uour.  Exper.  Med.,  1899  (4),  627.  2  Loc.  cif. 


CHAPTER    V 

CHEMISTRY  OF  THE  ANIMAL  PARASITES l 

THIS  subject  has  received  much  less  consideration  than  its 
importance  deserves,  and  we  are  quite  in  the  dark  as  to  how 
much  of  the  effects  produced  by  animal  parasites  are  not  merely 
mechanical,  but  are  due  to  soluble  poisons  that  they  may  secrete 
or  excrete.  Some  of  the  parasites  probably  cause  harm  mechan- 
ically and  in  no  other  way,  but  with  most  of  them  there  is  more 
or  less  evidence  of  the  formation  of  poisonous  substances.  The 
composition  of  the  bodies  of  the  animal  parasites  is  an  almost 
unexplored  field,  but  we  have  no  reason  to  believe  that  the  com- 
position of  the  cells  of  invertebrates  differs  essentially  from  that  of 
the  cells  of  higher  organisms.  Perhaps  the  most  characteristic 
constituent  observed  in  many  forms  is  chtim,  which  forms  a 
large  part  of  the  outer  covering  of  the  encysted  forms,  and  prob- 
ably of  many  of  the  worms.  Glycogen  is  usually  abundant  in 
the  invertebrates,  and  the  animal  parasites  form  no  exception, 2 
this  carbohydrate  having  been  found  in  their  bodies  by  many 
observers. 

Eosinophllia. — One  of  the  most  characteristic  features  of 
the  animal  parasites  is  that  they  exert  a  positive  chemotaxis, 
particularly  for  eosinophile  leucocytes.3 

An  increase  in  the  number  of  these  cells  in  the  blood,  as  well 
as  a  local  accumulation  in  the  tissues  nearest  the  parasite,  has 
been  observed  in  infection  with  the  following  parasites  : 4  Unci- 
naria  duodenalis,  Strongyloides  intestinalis,  Ascaris  lumbricoides, 
Tcenia  solium,  Tcenia  saginata,  Tcenia  echinococcus,5  Filaria 
bancrofti,  Bilharzia  hcematobia,  Trichinetta  spiralis,  and  Amoeba 
coli.G  Of  these,  infection  with  Trichinella  spiralis  causes  the 
most  pronounced  eosinophilia,  presumably  because  of  the  great 

1  General   references  to  this  subject  will  be  found  in  v.  Fiirth's  "  Vergleich- 
ende  chemische  Physiologic  der  niederen  Tiere,"  Jena,  1903 ;    and  Faust's 
"  Tierische  Gifte,"  Braunschweig,  1906. 

2  See  Pfluger,  Pfliiger's  Arch.,  1903  (96),  153. 

3  Literature  by  Opie,  Amer.  Jour.  Med.  Sci.,  1904  (127),  477;  and  Staubli, 
Deut.  Arch.  klin.  Med.,  1906  (85),  286. 

4  Literature  by  Bruns,  Liefmann  and  Mackel,  Munch,  med.  Woch.,  1905 
(52),  253. 

5  See  DeVe",  Compt.  Rend.  Soc.  Biol.,  1905  (59),  49. 
6 Billet,  Semaine  meU,  1905  (25),  261. 

9  129 


130  CHEMISTRY  OF  THE  ANIMAL  PARASITES 

number  of  parasites  present  in  the  tissues  at  once.  That  the 
eosinophilia  is  due  to  the  action  of  the  soluble  products  or  con- 
stituents of  the  parasites  has  been  shown  by  experimental  injec- 
tion into  animals  of  extracts  from  the  bodies  of  the  parasites.1 
Calamida  has  found  that  extracts  of  dog  tapeworms  also,  when 
placed  in  the  tissues  in  a  capillary  tube,  cause  an  accumulation  of 
eosinophile  cells  in  the  tube.  Experimental  infection  with  exces- 
sive numbers  of  trichinella  causes  a  rapid  diminution  in  the  number 
of  eosinophile  leucocytes,  which  also  show  evidences  of  disinte- 
gration in  the  bone-marrow  and  lymph-glands.  Such  large 
injections  are  fatal,  which  suggests  that  the  eosinophilia  has  a 
protective  influence.  In  favor  of  this  view  is  the  observation 
of  Milian, 2  who  found  that  sarcosporidia  in  beef  are  destroyed 
by  a  violent  leucocytic  reaction,  the  prevailing  cell  being  the 
eosinophile.  As  the  eosinophile  increase  does  not  occur  until 
several  days  after  the  infected  flesh  is  eaten,  the  chemotactic 
substance  is  not  liberated  from  the  encapsulated  trichinellse  when 
their  capsules  are  digested  off  in  the  gastric  juice,  but  comes 
either  from  the  free  larvae,  or  from  the  degenerated  muscles  in 
which  they  burrow.  Coincident  bacterial  infection  may  reduce 
the  number  of  eosinophiles. 

PROTOZOA 

These  unicellular  forms  possess  all  the  chemical  characters 
of  the  cells,  of  higher  forms,  even  to  the  more  specialized  con- 
stituents. Thus  it  has  been  demonstrated  that  protozoa  contain 
proteolytic  enzymes, 3  and  that  they  secrete  an  acid  into  their 
digestive  vacuoles.4  On  the  other  hand,  Amoeba  coli  does  not 
seem  to  digest  the  red  corpuscle  and  the  bacteria  that  it  takes 
up. 5  Whether  the  Amoeba  coli  produces  any  toxic  materials, 
specific  or  non-specific,  has  not  yet  been  determined,  but  the 
necrosis  that  it  produces  in  liver  abscesses,  when  bacterial  co- 
operation can  often  be  excluded  by  culture,  strongly  indicates 
the  production  of  necrogenic  substances.  Apparently  these  sub- 
stances are  not  chemotactic,  in  view  of  the  absence  of  leucocytic 
accumulation  which  is  characteristic  of  the  lesions  of  amebic 

1  If  Habershon's  views  (Jour.  Pathol.  and  Bacteriol.,  1906  (11),  95)  on  the 
relation  of  glycogen  to  the  eosinophile  granules  is  correct,  it  is  possible  that 
there  exists  some  relation  between  the  abundance  of  glycogen  in  the  animal 
parasites  and  their  tendency  to  cause  eosinophile  accumulations. 

2  Bull,  et  Mem.  Soc.  Anat.,  1901  (Ser.  6,  T.  3),  323. 
3Mouton,  ComptRend.  Soc.  Biol.,  1901  (53),  801. 

*Le  Dantec,  Ann.  Inst.  Pasteur,  1890  (4),  776;  Greenwood  and  Saunders, 
Jour,  of  Physiol.,  1894  (16),  441. 

5  Musgrave  and  Clegg,  Bureau  of  Gov't.  Laboratories,  Manila,  1904,  No.  18, 
p.  38. 


PROTOZOA  131 

dysentery.  There  is  also  no  evidence,  clinical  or  experimental, 
that  amebic  infection  causes  the  formation  of  anti-substances  of 
any  kind  in  the  body  of  the  host.  The  spontaneous  recovery 
from  amebic  and  other  protozoan  infections,  however,  may  be 
considered  as  indicating  the  development  of  an  immunity 
against  these  organisms.  Numerous  observers  have  suggested 
the  possibility  of  obtaining  artificial  immunity  against  protozoa, 
and  Rossle l  has  obtained  immune  sera  against  infusoria. 

Plasmodium  malarias  undoubtedly  produces  toxic  sub- 
stances, which  seem  to  be  of  such  a  nature  that  they  do  not 
diffuse  from  the  red  corpuscle,  but  are  only  liberated  when  the 
corpuscle  breaks  up  on  the  maturation  of  the  parasite.  In  this 
way  the  characteristic  paroxysmal  manifestations  of  the  disease 
are  produced.  The  nature  of  the  poison  or  poisons  is  unknown, 
but  we  have  evidence  that  it  is  hemolytic,  since  malarial  serum 
may  hemolyze  normal  corpuscles.2  Presumably  it  is  not  ex- 
tremely toxic  for  parenchymatous  cells,  since  the  parenchyma- 
tous  lesions  in  malaria  seem  to  be  relatively  slight  as  compared 
with  the  intensity  and  duration  of  the  intoxication.  Some 
authors  state  that  the  toxicity  of  the  urine  is  increased  after  the 
paroxysm,3  which,  however,  does  not  necessarily  indicate  that  a 
poison  formed  by  the  parasites  is  excreted  in  the  urine.  Immu- 
nity seems  to  be  seldom  developed  against  the  malarial  poison 
or  against  the  parasite  itself,  although  some  persons  seem  to  be 
naturally  immune,  while  some  acquire  immunity  through  previ- 
ous infection.4  Many  writers  have  looked  upon  the  pigment 
present  in  the  malarial  parasites  as  a  true  melanin,  produced  by 
their  metabolism  and  not  a  product  of  decomposition  of  hemo- 
globin; however,  Ewing5  found  that  it  showed  the  same  relation 
to  solvents  as  the  blood-pigments  (See  "  Pigmentation,"  Chapter 
xvi). 

Sarcosporidia  of  sheep  (Balbiania  gigantea,  Railliet) 
yield  aqueous  and  glycerin  extracts  that  are  highly  toxic  for 
rabbits  (Pfeiffer),  the  poisonous  constituent  of  which  was  called 
sarcocystin  by  Laveran  and  Mesnil.6  This  is  so  highly  toxic 
that  0.0001  gm.  is  fatal  to  rabbits  (per  kilo),  other  animals 
being  less  susceptible.  It  loses  its  toxicity  on  heating  at  85° 

1  Arch.  f.  Hyg.,  1905  (54),  1 ;  full  review  of  this  topic. 

2  See  Kegnault,  Revue  de  MeU,  1903  (23),  729. 

'Quoted  from  Blanchard,  Arch.  d.  Parasitol.,  1905  (10),  83;  this  article 
gives  a  resume  of  the  subject  of  the  toxic  substances  produced  by  the  animal 
parasites. 

4  See  Celli,  Cent.  f.  Bakt.,  1900  (27),  107. 

5  Jour.  Exper.  Med.,  1902  (6),  119. 
6Compt.  Kend.  Soc.  Biol.,  1899  (51),  311. 


132  CHEMISTRY  OF  THE  ANIMAL  PARASITES 

for  twenty  minutes,  and  is  somewhat  impaired  at  55-57°  for 
two  hours.  It  is  probable  that  the  pathogenic  protozoa,  at 
least  in  some  instances,  have  a  semipermeable  membrane  about 
them,  for  Goebel l  found  that  trypanosomes  are  very  susceptible 
to  changes  in  osmotic  conditions. 

CESTODES 

Tsenia  echinococcus  has  been  by  far  the  most  studied,  its 
abundant  fluid  content  furnishing  suitable  material  for  investi- 
gation. That  this  fluid  is  toxic  has  been  repeatedly  observed 
when,  through  rupture  or  puncture,  the  fluid  has  escaped  into 
the  body  cavities ;  such  accidents  are  often  followed  by  violent 
intoxication,  sometimes  by  death.2  The  most  constant  symp- 
toms are  local  irritation  and  inflammation,  accompanied  by 
urticaria,  which  may  also  be  produced  experimentally  in  man  if 
the  cyst  contents  are  injected  subcutaneously.  The  fluid  is  also 
highly  toxic  to  many  animals.  As  long  as  the  cyst  is  unopened 
no  toxic  manifestations  are  observed,  presumably  because  the 
toxic  substances  do  not  diffuse  through  the  cyst  wall.  The 
nature  of  the  toxic  substances  is  not  known,  although  Brieger 
isolated  a  platinum  salt  of  a  substance  that  killed  mice. 

The  fluid  of  the  echinococcus  cysts  has  generally  a  specific 
gravity  of  1005-1015,  and  contains  1.4-2  per  cent,  of  solids. 
Most  abundant  are  sodium  chloride,  about  0.8  per  cent.,  and 
sugar,  0.25  per  cent.,  the  latter  presumably  coming  from  the 
glycogen  contained  in  the  wall.  Cholesterin  is  often  abundant, 
while  inosite,  creatin,  and  succinic  acid  are  often  found.  Clerc 
has  found  traces  of  lipase,  but  other  enzymes  seem  to  be  absent 
or  in  very  small  amounts.  Proteids  are  present  only  in  traces, 
unless  inflammation  has  occurred.  Schilling3  found  the  molec- 
ular concentration  of  the  cyst  fluid  to  be  quite  the  same  as 
that  of  the  patient's  blood. 

The  cyst  wall  consists  of  a  hyaline  substance  which  seems  to 
stand  between  the  chitin  and  the  proteids,  and  probably  con- 
sists of  a  mixture  of  both.  Because  of  the  chitin  it  yields 
about  50  per  cent,  of  a  reducing,  sugar-like  body  when  boiled 
with  acids.  Glycogen  is  also  usually  present,  but  it  is  limited 
to  the  germinating  membrane.4 

Other  cestodes,  when  in  the  cystic  form,  contain  fluids  which 
are  more  or  less  toxic.  Thus  Moursou  and  Schlagdenhauffen 5 

1  Ann.  Soc.  Med.  d.  le  Gand.  1906  (86),  11. 

2  See  Achard,  Arch.  g&i.  de'Med.,  1887  (22),  410  and  572. 
3 Cent.  inn.  Med.,  1904  (25),  833. 

*Brault  and  Loeper,  Jour.  Phys.  et  Path,  gen.,  1904  (6),  295. 
5Compt.  Kend.  Soc.  Biol.,  1882  (95),  791. 


CESTODES  133 

found  a  "  leticomam  "  in  the  Cysticercus  tenuicollis,  the  larva  of 
Tcenia  marginata,  which  causes  urticaria  and  other  toxic  symp- 
toms when  injected  into  animals.  The  fluids  of  Cysticercus 
pisiformis  (the  common  cestode  of  rabbits)  have  been  found 
toxic  for  frogs,  and  Vaullegeard 1  has  determined  the  presence 
of  an  "  alkaloid  "  and  a  "  ferment  toxin  "  in  this  fluid.  The 
fluids  of  the  cysts  of  Ccenurus  cerebralis,  Ccenurus  serialis,  and 
Echinococcus  polymorphous  have  all  been  found  toxic,  and  it  is 
probable  that  this  is  a  general  rule  with  the  cestodes,2  but 
human  forms  other  than  the  echinococcus  seem  not  to  have  been 
investigated ; 3  according  to  Jammes  and  Mandoul,  extracts  of 
taenia  are  bactericidal. 

Dibothriocephalus  latus  frequently  causes  anemia,  which 
has  been  attributed  to  a  poison  liberated  by  the  parasite  when 
it  undergoes  disintegration,  and  possibly  as  a  secretion  of  the 
living  worm.4  All  the  intestinal  cestodes  are  equipped  with  a 
well-developed  excretory  apparatus,  and  it  is  easy  to  imagine 
that  their  excretory  products  may  be  toxic  to  the  animal  into 
whose  intestine  they  are  excreted.  Schauman  and  Tallqvist5 
found  that  extracts  from  these  worms  were  toxic  to  dogs  how- 
ever administered,  and  caused  a  marked  anemia ;  in  the  test- 
tube  these  extracts  were  hemolytic. 

Rosenqvist 6  has  studied  the  metabolism  of  twenty-one  cases 
of  bothriocephalus  anemia,  and  found  evidence  in  nearly  all  of 
a  toxogenic  destruction  of  proteid,  which  ceases  promptly  when 
the  worms  are  removed.  He  has  found  that  these  worms  pro- 
duce a  poison  which  is  globulicidal,  and  probably  also  generally 
cytotoxic,  since  in  the  anemias  that  they  produce,  the  elimination 
of  purin  bodies  of  tissue  origin  (endogenous  purin)  is  increased. 
The  nitrogenous  metabolism  is  quite  the  same  in  pernicious 
anemia  and  in  bothriocephalus  anemia.  Isaac  and  v.  d.  Velden 7 
state  that  the  blood  of  patients  infected  with  this  parasite  gives  a 
precipitin  reaction  with  autolytic  fluid  obtained  from  bothrio- 
cephalus, and  that  rabbits  immunized  with  such  autolytic  fluids 
developed  a  precipitin. 

Other  Taenia. — There  is  much  less  evidence  that  other  forms 
of  tsenia  produce  toxic  substances  which  injure  their  host, 
although  the  clinical  manifestations  observed  in  persons  harboring 
tsenia  are  often  of  such  a  nature  as  to  indicate  strongly  an 
intoxication.  Jammes  and  Mandoul 8  found  no  toxic  manifesta- 

1  Bull.  Soc.  linne'enne  de  Normandie,  1 901  (4),  84. 

2  Blanchard.,  foe  eit.  3  Semaine  meU,  1905  (25),  55. 

4 Literature  by  Blanchard,  loc.  tit.  5Deut.  med.  Woch.,  1898  (24),  312. 
6Zeit  klin.  Med.,  1903  (49),  193.  7Deut.  med.  Woch.,  1904  (30),  982. 
8Corapt.  Rend.  Acad.  Sci.,  1904  (138),  1734. 


134  CHEMISTRY  OF  THE  ANIMAL  PARASITES 

tions  produced  by  extracts  of  Tcenia  saginata,  which  negative 
finding  is  supported  by  Cao,1  and  by  Boycott,2  using  various 
sorts  of  tsenia.  These  results  contradict  the  earlier  positive 
findings  of  Messineo  and  Calamida,3  who  found  extracts  of 
tsenia  from  dogs  to  be  hemolytic,  chemotactic  (especially  for 
eosinophiles),  and  to  cause  local  fatty  degeneration  in  the  liver. 
Possibly  these  differences  in  results  are  due  to  the  fact  that  dif- 
ferent parasites  were  studied  by  different  investigators  ;  further- 
more, tests  of  toxicity  of  human  parasites  upon  rabbits  and 
guinea-pigs  can  hardly  be  considered  conclusive.  Le  Dantec 
did  not  find  a  precipitin  for  Tcenia  saginata  extracts  in  the  blood 
of  persons  harboring  this  parasite. 

Picou  and  Ramond 4  state  that  tsenia  extracts  undergo  putre- 
faction very  slowly,  and  attribute  this  to  a  bactericidal  property. 
Weinland5  has  found'  that  many  intestinal  parasites  exhibit 
antitryptic  properties,  but  in  a  study  of  the  histological  changes 
of  autolysis  I  observed  a  ta?nia  in  the  intestine  of  a  dog  undergo 
more  rapid  karyolytic  changes  than  did  the  intestinal  epithelium. 
Dastre  and  Stessano 6  state  that  extracts  of  Tcenia  serrata  act 
upon  enterokinase,  rather  than  on  trypsinogen. 

NEMATODES 

Ascaris. — The  toxicity  of  members  of  this  group  is  a 
matter  of  dispute,  although,  as  with  the  Tcenia,  there  have 
been  observed  in  patients  symptoms  that  were  more  easily 
explained  as  due  to  chemical  substances  than  as  due  to  mechani- 
cal irritation.  Miram,7  while  studying  Ascaris  megalocephala, 
suffered  from  attacks  of  sneezing,  lachrymation,  itching,  and 
swelling  of  the  fingers,  v.  Linstow  suffered  from  a  severe 
attack  of  conjunctivitis  with  chemosis  after  touching  his  eye 
with  a  finger  that  had  been  in  contact  with  one  of  these  worms. 
Others  have  had  similar  experiences,  and  it  has  been  found 
that  the  fluid  from  these  worms  is  toxic  to  rabbits  (Arthus 
and  Chanson,8  Vaullegeard 9 ).  Blanchard,  nevertheless,  con- 
siders that  the  toxic  manifestations  observed  in  patients 
infected  with  these  worms  are  most  probably  due  to  bacterial 
infection  of  the  injured  intestinal  mucosa.  Jammes 10  found 

^iforma  med.,  1901  (3),  795. 
2  Jour.  Pathol.  and  Bacteriol.,  1905  (10),  383. 
3 Cent.  f.  Bakt,  1901  (30),  346  and  374. 
*Compt.  Kend.  Soc.  Biol.,  1899  (51),  176. 
5Zeit.  f.  Biol.,  1902  (44),  1  and  45. 
6Compt.  Rend.  Soc.  Biol.,  1903  (55),  130. 

7  Quoted  by  Nuttall,  Amer.  Naturalist,  1899  (33),  247. 

8  Cent.  f.  Bakt.,  1896  (20),  264. 

9  Quoted  by  Blanchard,  loc  cit.,  p.  98. 

10  Assoc.  francaise  pour  Pavancement  des  sciences,  1902  (31),  241. 


NEMATODES  135 

that  A.  lumbricoides  and  Oxyuris  vermicularis  do  not  produce 
toxic  materials,  and  Boycott  *  obtained  a  negative  result  with 
extracts  of  A.  lumbricoides  filtered  through  porcelain  to  exclude 
bacteria.  Allaria2  also  obtained  negative  results,  and  could 
demonstrate  no  hemolytic  properties.  On  the  other  hand, 
Cattaneo 3  claims  that  filtered  culture-media  in  which  Ascaris 
has  lived  for  some  time  is  toxic  for  guinea-pigs. 

Weinland  first  demonstrated  that  Ascaris  and  other  intestinal 
worms  are  able  to  live  in  the  digestive  fluids  of  the  intestine 
because  they  contain  an  active  antitrypsin.  Dastre  and  Stassano 
considered  the  active  agent  an  antikinase,  but  Weinland's  view 
has  been  confirmed  by  Hamill.4 

Glycogen  has  been  found  abundantly  in  ascaris,  and  chitin 5  is 
present  in  the  external  covering  of  some  forms.  Reichard  6  found 
that  in  A.  lumbricoides  and  A.  sipunculides  the  cuticle  is  formed 
of  an  albuminoid  material,  but  in  the  Hirudines  it  is  a  true  chitin. 

Trichinella  spiralis  unquestionably  produces  toxic  sub- 
stances, as  shown  by  the  profound  intoxication  and  febrile  con- 
dition of  persons  suifering  from  infection  with  this  parasite.  As 
to  the  nature  of  the  poison,  however,  we  know  nothing,  except 
that  it  causes  cellular  degeneration,  and  is  particularly  chemo- 
tactic  for  eosinophiles. 

Uncinaria  duodenalis,  which  has  for  its  chief  effect  the  pro- 
duction of  a  severe  anemia,  seems  to  cause  this  anemia  by  pro- 
ducing repeated  small  hemorrhages  rather  than  by  any  toxic 
action.  The  abundance  of  this  loss  of  blood  is  explained  by  L. 
Loeb 7  as  due  to  the  presence,  in  the  anterior  portion  of  the  para- 
site (Ankylostoma  caninum),  of  a  substance  that  inhibits  the 
coagulation  of  the  blood,  analogous  to  the  "hirudin"  of  the  leech. 

Filaria  seem  not  to  produce  any  appreciable  amount  of  toxic 
material,  if  we  may  judge  by  the  slight  evidence  of  intoxication 
shown  by  infected  individuals.  An  exception  may  be  made  in 
the  case  of  the  guinea-worm  (Dracunculus  or  F.  medinensis). 
This  parasite  causes  chiefly  mechanical  injury  unless  its  body  is 
ruptured,  which  may  happen  in  attempting  to  remove  it  forcibly ; 
this  accident  is  followed  by  violent  local  inflammation  or  gan- 
grene, which  indicates  that  some  powerfully  irritant  substance  is 
liberated  from  the  torn  body  of  the  worm. 

Loc.  cit.  2  Kef.  in  Cent.  f.  Bakt.,  1905  (35),  539. 

Eef.  in  Biochem.  Centr.,  1903  (1),  806. 
Jour,  of  Physiol.,  1906  (33),  479;  literature. 
Weinland,  Zeit.  f.  Biol.,  1902  (43),  86. 

"  Ueber  Cuticular-  und  Geriist-substanzen  bei  wirbellosen  Tieren,"  Heidel- 
berg, 1902. 

7  Cent.  f.  Bakt.,  1904  (37),  93 ;  1906  (40),  740. 


CHAPTER    VI 

CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 
AND  THEIR  PRODUCTS,  AND  THE  REACTIONS 
OF  AGGLUTINATION  AND  PRECIPITATION1 

BY  the  application  of  chemical  principles  to  the  problems 
of  immunity,  Ehrlich  developed  a  hypothesis  concerning  the 
nature  of  the  action  of  bacterial  toxins  upon  the  cells,  and 
of  the  process  of  antitoxin  formation,  which  has  served  most 
successfully  as  a  working  hypothesis.  The  true  toxins  are  of 
so  labile  a  nature,  so  readily  destroyed  by  chemical  agencies, 
and  so  elusive  of  isolation,  that  their  chemical  natures  and 
properties  remain  quite  unknown,  and  they  can  be  detected 
only  by  their  biological  action.  Against  other  sorts  of  poisons 
with  simpler  composition  the  animal  body  does  not  develop  an 
immunity  in  the  same  sense  that  it  does  against  bacterial  and 
similar  poisons,  and  so  in  studying  the  reactions  of  immunity 
we  cannot  have  the  advantage  of  having  at  least  one  of  the 
factors  a  substance  of  known  chemical  nature.  By  immuniza- 
tion or  habituation  a  certain  degree  of  resistance  can  be  obtained 
against  some  alkaloidal  poisons,  e.  g.,  morphine,  but  it  is  not 
of  the  same  nature  as  the  immunity  against  bacterial  toxins,  for 
the  blood-serum  does  not  acquire  any  substances  capable  of 
neutralizing  the  poisons.  The  resistance  against  such  poisons 
must,  therefore,  be  considered  apart  from  the  question  of 
immunity  against  bacterial  infection  (see  Chapter  vii) ;  but 
with  the  latter  may  be  included  the  consideration  of  immunity 
artificially  developed  in  the  body  against  foreign  proteids,  tissues, 
and  cells. 

Immunity  against  bacteria  may  be  divided  into  several  sub- 
jects, namely,  immunity  against  bacterial  toxins,  against  bacterial 
proteids  and  enzymes,  and  against  the  bacteria  themselves, 
including  the  phenomenon  of  agglutination.  The  products 


and  Serum  Therapy"  by  Kicketts,  Chicago,  1906.  For  bibliography  see 
Kolle  and  Wassermann,  1903,  Bd.  4.  Later  references  of  importance  have 
been  cited  in  the  foot-notes  of  this  chapter. 

136 


TOXINS  AND  ANTITOXINS  137 

formed  by  bacterial  decomposition  of  proteids,  the  ptomains, 
do  not  give  rise  to  immune  substances. 

TOXINS    AND    ANTITOXINS 

The  first  phase  of  immunity  to  be  considered  is  the  neutrali- 
zation of  toxin  by  antitoxin,  since  it  is  the  most  complete  and 
best  understood  of  the  reactions  of  immunity.  In  the  preceding 
chapter  on  the  bacteria  and  their  products  the  nature  of  the 
true  toxins  was  defined,  and  attention  was  called  to  the  fact 
that  one  of  their  most  important  characteristics  is  that  immuni- 
zation of  animals  against  them  leads  to  the  accumulation  in  the 
blood  of  substances  capable  of  completely  neutralizing  their 
poisonous  action.  Such  true  toxins  are  produced  especially  by 
the  diphtheria  bacillus  and  the  tetanus  bacillus,  also,  but  less 
strikingly,  by  B.  pyocyaneus,  B.  botulinus,  and  possibly  by  a 
few  others.  In  addition  to  these,  numerous  bacteria  produce 
hemolytic  poisons  which  seem  to  have  properties  similar  to  the 
toxins ;  and  there  are  also  toxins  produced  by  plants  (abrin, 
ricin,  crotin,  and  mushroom  poisons)  and  by  animals  (snake 
venom,  scorpion  and  spider  toxin,  and  eel  serum).  Against  all 
of  these,  true  antitoxins  may  be  obtained  by  the  immunization 
of  animals. 

Ehrlich's  Conception  of  Toxins  and  Antitoxins. — 
According  to  Ehrlich's  theory,  the  action  of  toxins  upon  cells 
is  purely  chemical.  A  toxin  unites  with  a  cell  because  some 
chemical  group  in  the  molecule  of  toxin  has  a  chemical  affinity 
for  some  particular  group  in  the  cell  protoplasm.  For  con- 
venience in  description  names  have  been  given  to  these  groups ; 
the  group  of  the  toxin  that  combines  with  the  cell  has  been 
called  the  haptophorous  group,  or  haptophore,  while  the  group 
in  the  protoplasm  that  combines  with  the  toxin  is  known  as  the 
receptor.1  It  has  been  found  that  after  being  kept  for  some 
time,  or  when  placed  under  certain  unfavorable  conditions,  the 
toxin  loses  its  poisonous  properties  without  losing  its  power  to 
combine  with  cells,  as  shown  by  the  fact  that  immunization  with 
such  altered  toxin  gives  rise  to  the  formation  of  antitoxin. 

1  Ehrlich  has  used  certain  diagrams  to  illustrate  these  various  groups  and 
their  relations  to  the  cells  and  to  one  another,  which  are  generally  used  in 
explaining  his  theory.  From  a  teaching  standpoint  they  have  seemed  to  be 
undesirable,  in  that  the  student  soon  comes  to  ascribe  physical  properties  and 
appearances  to  what  should  be  considered  as  chemical  combinations.  The 
toxophore  group  becomes  "  the  black  fringed  end  of  the  toxin,"  etc.  To  one 
accustomed  to  thinking  in  chemical  terms  there  is  no  difficulty  in  following 
the  literature  and  understanding  the  reactions  as  chemical  reactions,  which 
they  are. 


138     CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 

Therefore  it  is  not  the  haptophore  that  causes  the  harm  to  the 
cell,  but  there  must  be  some  other  group  with  this  particular 
function.  To  the  group  that  produces  the  harm  the  name  toxo- 
phore  is  given.  If  all  the  receptors  of  a  cell  are  combined  by 
toxin  molecules  that  have  lost  their  toxophore  group  (toxoid  is 
the  name  given  to  such  altered  toxins),  the  cell  cannot  then  be 
injured  by  the  corresponding  active  toxin,  showing  that  the 
toxin  must  first  become  united  to  a  cell  receptor  by  its  hapto- 
phore group  before  the  toxophore  group  can  cause  an  injury. 

Animals  that  are  naturally  immune  to  toxins  may  owe  their 
immunity  to  the  fact  that  their  vital  tissues  contain  no  sub- 
stances with  a  chemical  affinity  for  the  toxin,  and  hence  the 
toxin  cannot  unite  with  them  to  cause  harm.  (In  Ehrlich's 
terminology,  the  cells  contain  no  receptors  for  the  toxin.)  The 
toxin  may  not  combine  with  any  tissue  element  at  all  in  such 
immune  animals,  and  circulate  for  some  time  harmlessly  in  the 
blood ;  or  it  may  combine  with  some  organ  where  it  does  little 
harm,  e.  g.,  tetanus  toxin  is  said  to  combine  chiefly  in  the  liver 
of  some  animals,  and  therefore  it  does  not  harm  their  nervous 
system. 

According  to  this  theory,  the  antitoxin  consists  of  cell  receptors 
that  have  been  produced  in  excess  and  secreted  by  the  cells  into  the 
blood.  In  the  blood  they  combine  with  any  toxin  that  may 
have  been  introduced,  and  by  saturating  its  affinities  render  it 
incapable  of  uniting  with  the  cells.  As  the  toxin  harms  cells 
only  after  it  has  been  chemically  united  to  them,  it  is  rendered 
harmless  when  its  affinities  for  the  cell  (the  haptophore  groups) 
are  saturated  by  cell  receptors  in  the  blood  stream.  The  process 
of  immunization  consists  in  injuring  the  body  cells  to  such  a 
degree  that  they  are  stimulated  to  regenerate  the  receptor  groups 
with  which  the  toxin  combines;  these  receptor  groups  are  produced 
in  excess,  and  not  only  replace  those  combined  by  the  toxins, 
but  the  excessive  groups  escape  free  into  the  blood.  Hence  the 
serum  of  an  immunized  animal  is  antitoxic  because  it  contains 
free  cell  receptors  that  can  unite  with  the  toxin.  An  important 
point  is  that  the  receptors  liberated  by  all  animals  which  have 
been  immunized  with  a  given  toxin  seem  to  be  the  same — horse 
serum,  or  sheep  serum,  or  goat  serum  will  neutralize  diphtheria 
toxin  if  the  animals  have  been  made  immune  to  this  toxin; 
and,  furthermore,  their  serum  when  introduced  into  the  body  of 
an  entirely  different  animal,  e.  g.,  a  guinea-pig,  will  neutralize 
diphtheria  toxin  within  its  body.  Equally  important  is  the 
fact  that  the  antitoxin  for  one  toxin  will  not  neutralize  any 
other  toxin ;  e.  g.,  diphtheria  antitoxin  will  not  neutralize 


TOXINS  AND  ANTITOXINS  139 

tetanus  toxin,  or  conversely.  This  means  that  diphtheria  toxin 
is  attached  to  chemical  groups  of  the  body  cells  (receptors) 
which  are  quite  different  from  the  groups  to  which  tetanus 
toxin  unites,  and  hence  different  receptors  are  thrown  out  in 
immunizing  against  each. 

The  neutralization  of  toxin  by  antitoxin  is  distinctly  a  chemi- 
cal process,  which  occurs  as  well  in  the  test-tube  as  in  the  body. 
It  occurs  according  to  the  laws  of  definite  proportion,  a  given 
amount  of  antitoxin  neutralizing  a  proportionate  amount  of 
toxin  under  equal  conditions  (hence  the  toxin  is  not  destroyed 
by  antitoxin  through  a  ferment  action,  as  was  at  first  suggested). 
Neither  the  toxin  nor  the  antitoxin  is  destroyed  in  the  process 
of  neutralization,  as  has  been  proved  by  suitable  experiments, 
but  they  appear  to  be  chemically  united  to  each  other,  as  any 
two  large  molecules  may  be.  Neutralization  occurs  more 
rapidly  under  the  influence  of  warmth,  and  more  slowly  in  the 
cold;  and  it  is  more  rapid  in  concentrated  than  in  dilute  solu- 
tions, just  as  with  ordinary  chemical  reactions.  According  to 
Arrhenius  and  Madsen,  the  reaction  of  antitoxin  upon  toxin  is 
accompanied  by  the  liberation  of  much  heat — 6600  cal.  per 
gram  molecule,  or  about  half  as  much  as  is  set  free  by  the  action 
of  a  strong  acid  upon  a  strong  base.1  On  dilution  of  a  neutral 
toxin-antitoxin  mixture,  a  certain  amount  of  dissociation  seems 
to  occur.2 

There  is  no  relation  between  antitoxins  and  enzymes.  The 
antitoxin  acts  quantitatively,  and  produces  no  detectable  altera- 
tion in  the  toxin,  or  in  any  other  substance,  as  far  as  we  know. 
It  also  has  but  one  functionating  group  (haptophore),  the  one 
with  which  it  combines  with  the  toxin ;  whereas  both  toxins 
and  enzymes  seem  to  have  two  functionating  groups,  one  which 
unites  with  the  cell  or  substance  that  is  to  be  attacked,  the  other 
which  produces  the  chemical  changes. 

CHEMICAL  NATURE  OF  ANTITOXINS 

This  is  as  entirely  unknown  as  is  the  nature  of  the  toxins. 
Investigation  of  antitoxic  serum  (principally  diphtheria  anti- 
toxin) has  shown  that  the  antitoxic  properties  are  closely  related 
to  the  serum  globulin,  which,  however,  by  no  means  proves 
that  antitoxin  is  serum  globulin  or  any  other  sort  of  a  proteid. 
According  to  Ehrlich's  theory,  antitoxin  consists  of  free  cell 
receptors,  and  these  receptors  are  presumably  simple  chemical 

1  Literature  of  chemical  and  physical  reactions  of  toxin  and  antitoxin  given 
by  Zangger,  Cent.  f.  Bakt.  (ref.),  1905  (36),  238. 

2  See  Otto  and  Sachs,  Zeit.  exp.  Path.  u.  Ther.,  1906  (3),  19. 


140     CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 

groups  which  may  be  but  a  part  of  a  larger  molecule,  or  they 
may  be  entire  proteid  molecules.  In  any  event  they  behave 
as  colloids l  •  moving  toward  the  anode  in  an  electrical  field, 
diffusing  little  or  not  at  all,  their  reaction  curve  resembling 
more  an  absorption  curve  than  the  reaction  curves  of  crystal- 
loids, and  being  influenced  by  all  conditions  that  influence 
colloids.  Whether  the  receptor  groups  are  secreted  in  a  free 
condition  in  antitoxin  formation  or  combined  in  a  large  mole- 
cule is  unknown. 

By  saturating  serum  with  magnesium  sulphate,  or  half  satur- 
ation with  ammonium  sulphate,  three  chief  groups  of  proteids 
can  be  precipitated  and  isolated.2  These  are  fibrinogen,  euglob- 
ulin  (true  globulin),  and  pseudo-globulin  (soluble  in  water). 
Belfanti  and  Carbone3  found  that  diphtheria  antitoxin  was 
carried  down  in  the  globulins  obtained  by  salting  out  with 
ammonium  or  magnesium  sulphates,  but  not  in  the  precipitates 
obtained  with  acetic  acid.  Atkinson  4  found  that  the  globulin 
thrown  down  on  saturating  serum  with  magnesium  sulphate 
contained  all  the  antitoxin.  Reprecipitating  this  globulin  with 
NaCl  at  different  temperatures  in  five  different  fractions,  each 
fraction  was  found  to  contain  a  part  of  the  antitoxin,  the  five 
fractions  together  containing  the  entire  antitoxic  strength. 

Glaessner5  could  not  find  any  perceptible  increase  in  the 
amount  of  globulin  in  the  serum  after  immunization.  Pick 6 
found  that  the  precipitate  obtained  by  36  per  cent,  vol- 
ume saturation  with  ammonium  sulphate  contained  no  anti- 
toxin ;  the  antitoxin  came  down  in  the  precipitate  obtained  on 
raising  the  strength  from  above  38  per  cent,  to  46  per  cent. 
According  to  Pick,  in  horse  serum  the  antitoxin  is  associated 
with  the  pseudo-globulin.  He  gives  the  following  table  of 
distribution  of  different  immune  bodies  in  the  serum  of  differ- 
ent animals : 

Fibrino  Pseudo- 

Immune  body.  globulin.  Euglobulin.       globulin.       Albumin. 

Diphtheria  antitoxin  ...    0               Goat  Horse  0 

Tetanus  antitoxin        ...    0  Goat  milk  (?)  0 

Cholera  hemolysin      ...    0              Goat  0  0 

Typhoid  agglutinin    ...    0                f  Goat,  rabbit,  Horse  0 

t  Guinea-pig 

Cholera  agglutinin      ...   0              Horse,  goat  0  0 

1SeeZangger  (loc.  cit.). 

2  See  resume  by  Gibson,  Jour.  Biol.  Chem.,  1905  (1),  161.     Literature  in 
"  Toxine  und  Antitoxine,"  Oppenheimer,  1904,  p.  81. 

3  Cent.  f.  Bakt,  1898  (23),  906. 

4  Jour.  Exper.  Med.,  1901  (5),  67. 

5  Zeit.  f.  exp.  Path.  u.  Ther.,  1905  (2),  154. 

6  Hofmeister's  Beitr.,  1901  (1),  351. 


CHEMISTRY  OF  ANTITOXINS  141 

Atkinson l  attempted  to  determine  the  proteid  nature  of  anti- 
toxin by  the  biological  method  (i.  e.,  by  means  of  the  precipitin 
reaction).  He  immunized  rabbits  with  globulin  obtained  from 
normal  horse  serum  and  with  globulin  from  antitoxic  serum, 
and  in  either  case  obtained  a  serum  precipitating  the  globulin 
of  antitoxic  serum,  and  with  it  all  the  antitoxin.  This  experi- 
ment merely  shows  that  the  antitoxin  is  carried  down  with  the 
globulin  precipitates  and  does  not  prove  that  it  is  itself  a  globu- 
lin. When  the  precipitating  serum  was  added  to  a  neutral 
mixture  of  toxin  and  antitoxin,  it  did  not  separate  the  antitoxin 
from  the  toxin  and  leave  the  latter  free,  indicating  that  the 
toxin-antitoxin  union  is  quite  firm. 

The  relation  of  antitoxins  to  proteids  has  also  been  investi- 
gated by  permitting  digestive  enzymes  to  act  on  antitoxic  serum. 
Pick 2  digested  the  antitoxin-containing  globulin  of  horse  serum 
for  several  days  with  trypsin ;  after  five  days,  when  part  of  the 
albumin  was  still  not  digested,  the  antitoxin  was  but  little  im- 
paired in  strength ;  after  nine  days,  when  most  of  the  proteid 
was  digested,  the  antitoxin  had  lost  two- thirds  of  its  strength. 
This  indicates  a  considerable  resistance  of  antitoxin  to  trypsin, 
but  also  shows  that  it  is  affected  in  much  the  same  way  as  the 
globulin  (which  is  itself  very  resistant  to  trypsin)  and  therefore 
is  presumably  of  similar  nature.  Antitoxin  seemed  to  be  much 
more  rapidly  destroyed  by  pepsin-HCl  digestion  than  by  tryp- 
sin, in  which  respect  it  again  resembles  the  serum  globulin. 

In  favor  of  the  view  that  antitoxin  is  a  definite  proteid  body 
is  also  the  fact  that  it  is  not  carried  down  in  indifferent  precip- 
itates, as  are  the  enzymes,  but  comes  down  always  in  a  certain 
fraction  of  the  proteid  precipitates,  e.  g.,  we  can  precipitate  all 
the  serum  albumin  from  an  antitoxic  serum,  and  it  does  not 
carry  down  with  it  any  of  the  antitoxin.  Another  important 
point  has  been  brought  out  by  Arrhenius  and  Madsen,3  who 
determined  approximately  the  molecular  weight  of  toxin  and 
antitoxin  by  means  of  their  rate  of  diffusion,  and  found  that 
the  toxin  (diphtheria  toxin  and  tetanolysin)  diffused  ten  or  more 
times  as  rapidly  as  the  corresponding  antitoxin.  This  indicates 
that  the  antitoxin  molecules  are  much  larger  than  the  toxin 
molecules,  agreeing  with  the  idea  that  antitoxin  is  of  proteid 
nature  and  that  toxin  is  not. 

Taken  all  together,  the  evidence  indicates  a  closer  resemblance 
of  antitoxins  to  proteids  than  has  been  shown  for  the  toxins, 

1  Medical  News,  1904  (84),  375. 

2  LOG.  tit. 

3  Festskrift  Statens  Serum  Institut,  1902. 


142     CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 

and  all  attempts  to  separate  antitoxins   from   proteids  have  so 
far  failed.1 

Antitoxins  are  retained  to  greater  or  less  extent  by  porcelain 
filters,  do  not  pass  through  dialyzing  membranes  readily,  and 
are  in  general  easily  destroyed  by  chemical  and  physical  agen- 
cies, although  much  less  so  than  are  most  toxins.  Heating  to 
60°-70°  injures,  and  boiling  quickly  destroys  them,  although 
like  the  enzymes  and  the  proteids,  they  resist  dry  heat  to  140°, 
and  also  extremely  low  temperature,  without  change.  Putre- 
faction of  the  serum  destroys  the  antitoxins  (Brieger2).  They 
can  be  preserved  for  a  very  long  time  when  dried  completely, 
but  in  the  serum  they  gradually  disappear,  especially  if  exposed 
to  light  and  air.  Acids  and  alkalies  destroy  antitoxins,  acids 
being  the  more  harmful  in  low  concentrations.  They  are  de- 
stroyed in  the  alimentary  tract,  without  appreciable  absorption, 
except  in  the  case  of  new-born  animals  suckling  mothers  whose 
blood  and  milk  contain  antitoxin  (Romer  and  Much 3 ).  When 
subcutaneously  injected,  antitoxin  soon  disappears  from  the 
blood ;  part  may  be  bound  to  the  tissues,  part  may  be  destroyed, 
since  only  traces  appear  in  the  urine. 

Toxicity  of  Serum. — Antitoxin  itself  seems  to  be  quite  free  from 
poisonous  effects.  The  intoxications  observed  after  injections  of  anti- 
toxic serum  are  not  due  to  the  antitoxin,  but  to  the  serum  itself.  Foreign 
serums,  as  well  as  proteids  of  all  kinds,  sometimes  exert  a  markedly 
poisonous  influence  upon  animals  into  whose  circulation  they  have  been 
introduced.  This  is  manifested  not  only  by  sickness  and  anatomical 
lesions,  but  also  by  the  production  of  specific  precipitating  bodies  in 
the  blood  (see  "Precipitins").  But  if  we  inject  antitoxic  serum  (for 
diphtheria)  derived  from  horse  blood  into  another  horse,  it  is  quite 
without  toxic  effect. 

An  interesting  phenomenon  has  been  observed  in  the  immunization 
of  animals,  namely,  that  whereas  a  small  dose  of  a  foreign  serum  may 
be  borne  without  serious  effects,  a  repetition  of  the  injection  after  an 
interval  of  ten  days  or  more  is  followed  by  profound  and  often  rapidly 
fatal  intoxication  (this  has  been  called  the  Theobald  Smith  phenomenon). 
The  first  dose  of  serum  makes  the  animal  susceptible  to  even  a  small 
dose  of  the  same  serum  (and  somewhat  susceptible  to  other  serums) 
which  seem  to  act  on  the  respiratory  center.  As  small  a  quantity  of 

1  An  exception  is  claimed  by  Proscher  (Munch,  med.  Wochenschr.,  1902 
(49),  1176),  which  Brieger  could  not  substantiate  (Festschrift  f.  Koch,  1903, 
p.  445).    Homer  (quoted  by  v.  Behring,  Beitr.  z.  exp.  Therap.,  1905,  Heft  10, 
p.  22)   found  that  tetanus  antitoxin  will  partly  escape  through  a  dialyzing 
membrane,  and  in  the  antitoxin-containing  dialysate  no  proteid  can  be  found 
by  ordinary  precipitation  reactions  ;  but  by  ultra-microscopic  methods  proteids 
can  be  found  in  every  antitoxin-containing  dialysate. 

2  Behring  states  that  tetanus  antitoxin  resists  putrefaction. 

3  Jahrb.  f.  Kinderheilk.,  1906  (13),  684. 


IMMUNITY  AGAINST  BACTERIAL  CELLS  143 

horse  serum  as  from  0.004  to  0.000001  c.c.  was  found  sufficient  to 
render  a  guinea-pig  susceptible,  and  0.1  c.c.  was  sufficient  to  kill  a 
guinea-pig  that  had  been  thus  sensitized.  Possibly  this  fact  of  devel- 
opment of  susceptibility  may  play  an  important  part  in  the  cases  of 
intoxication  following  administration  of  antitoxic  serum.1 

IMMUNITY  AGAINST  BACTERIAL  CELLS 

By  far  the  greater  number  of  pathogenic  bacteria  do  not 
produce  true  soluble  toxins,  but  form  toxic  materials  which 
accumulate  within  the  cells,  endotoxins  ;  these  produce  intoxica- 
tion only  when  the  bacterial  cells  are  disorganized,  liberating  the 
endotoxins.  Against  such  endotoxins  no  antitoxic  substances 
have  yet  been  produced  by  immunization.2  The  same  is  true  of  the 
non-specific  bacterial  proteids.  A  certain  degree  of  immunity 
can  be  conferred  to  animals  against  the  poisonous  proteids  iso- 
lated from  various  bacteria  in  Vaughan's  laboratory,3  but  it  is 
not  comparable  in  any  way  to  antitoxic  immunity.  Hence  these 
endocellular  poisons  are  in  some  way  different  from  the  true 
soluble  toxins. 

If  we  immunize  an  animal  against  living  bacteria,  or  against 
the  dead  bodies  of  bacteria,  or  against  endotoxins,  and  examine 
the  properties  of  its  serum,  we  find  that  although  the  serum  is 
powerless  to  neutralize  the  poisonous  effects  of  the  bacterial 
constituents,  it  does  possess  other  marked  properties,  which  are 
quite  the  same  no  matter  which  of  the  materials  mentioned  was 
used  in  immunization.  The  serum  will  kill  bacteria  both  in 
the  test-tube  and  in  the  animal  body ;  that  is,  it  is  bactericidal. 
It  contains  substances  that  cause  the  bacteria  to  agglutinate, 
called  agglutinins;  and  if  motile,  to  lose  their  motility.  It 
contains  substances  that  render  the  bacteria  more  readily  ingested 
by  phagocytes ;  these  substances  are  called  opsonins.  And  also 
this  serum  will  inhibit  the  action  of  the  bacterial  enzymes,  and 
will  produce  a  precipitate  in  solution  of  the  bacterial  proteids, 
•  i.  e.,  it  contains  antienzymes  and  precipitins.  All  these  proper- 
ties are,  to  a  certain  extent,  specific ;  that  is,  they  are  exerted 
chiefly  or  solely  against  the  particular  form  of  organism 
that  was  used  in  immunizing.4  Each  property  is  also  quite 

1  Full  discussion  by  Rosenau  and  Anderson,  Bull.  No.  29,  U.  S.  Gov't 
Hygienic  Lab.,  1906;  Jour.  Med.  Kesearch,  1906  (15),  179.  Also  see  Wolff- 
Eisner,  Cent.  f.  Bakt.,  1906  (40),  634;  and  Otto  in  v.  Leuthold's  Gedenkschr., 
1906  (1),  1. 

2Besredka  (Ann.  Inst.  Pasteur,  1906  (20),  149)  and  a  few  others  claim  to 
have  secured  antiendotoxins. 

3  American  Med.,  1905  (10),  145. 

*  Welch  (Med.  News,  1902  (81),  721)  has  suggested  that  possibly  the  bac- 
teria in  their  turn  may  develop  antibodies  for  the  tissues  and  fluids  in  which 
they  are  growing.  If  so,  we  have  a  reasonable  explanation  of  the  development 


144     CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 

distinct  from  the  others  and  may  therefore  be  considered  by 
itself. 

BACTERICIDAL  SERUM 

The  bactericidal  property  of  serum  may  be  shown  by  its 
destruction  of  the  life  manifestations  of  bacteria  without  marked 
alteration  in  their  structure,  or  it  may  be  accompanied  by  dis- 
solution of  the  bacterial  cell  (bacteriolysis).  How  much  of  the 
bacteriolytic  process  is  performed  by  the  serum  itself,  or  how 
much  by  the  autolytic  enzymes  of  the  bacterial  cell,  is  unknown, 
but  the  latter  is  probably  an  important  factor.  The  bactericidal 
property  of  immune  serum  has  been  shown  to  be  quite  inde- 
pendent of  the  antitoxic  properties  and  also  to  have  quite  a  dif- 
ferent mechanism.  This  last  is  shown  in  the  following  manner  : 

If  we  heat  bactericidal  serum  made  by  immunizing  an  animal 
against  bacteria,  say  the  cholera  vibrio,  at  55°  for  fifteen  minutes, 
it  will  be  found  to  have  lost  its  power  of  destroying  these  organ- 
isms. Normal  serum  of  non -immunized  animals  is  equally  with- 
out effect  upon  the  vibrios.  If,  however,  we  add  to  the  inactive 
heated  serum  an  equal  quantity  of  inactive  normal  serum,  the 
mixture  will  be  found  to  be  as  actively  bactericidal  as  the  orig- 
inal unheated  immune  serum.  This  phenomenon  is  interpreted 
to  mean  that,  by  immunization,  some  new  substance  has  been 
developed  which,  although  by  itself  incapable  of  destroying 
bacteria,  is  able,  when  united  with  some  substance  present  in 
normal  serum,  to  destroy  bacteria  readily.  The  substance  pres- 
ent in  normal  serum  is  also  incapable  of  affecting  bacteria  by 
itself,  but  needs  the  presence  of  the  substance  developed  by 
immunizing  to  render  it  bactericidal.  Hence  the  bactericidal 
property  in  this  case  depends  on  two  substances  acting  together : 
one,  developed  during  immunization  and  therefore  called  the 
immune  body,  is  specific  for  the  variety  of  bacteria  used  in  immu- 
nization, and  is  not  destroyed  by  heating  at  55°.  The  other, 
present  in  normal  serum,  is  not  increased  during  immunization, 
is  not  (altogether)  specific  in  character,  and  is  destroyed  by 
heating  at  55°  ;  as  its  action  is  complementary  to  that  of  the 
specific  immune  body,  it  is  called  the  complement. 

It  is  believed  that  the  action  of  these  substances  is  as  follows  : 
The  immune  body  is,  like  antitoxin,  a  cell  receptor  which  unites 

by  bacteria  of  marked  selective  action  for  specific  cells  of  the  host ;  e.  g.,  leucp- 
lysins,  endotheliolysins,  hemolysins,  etc. ;  and  also  the  peculiar  manner  in 
which  bacteria  often  attack  only  certain  tissues,  e.  g.,  multiple  septic  arthritis. 
The  fact  that  bacteria  are  said  to  develop  enzymes  with  specific  effects  accord- 
ing to  the  media  upon  which  they  grow  is  in  support  of  this  hypothesis. 


AMBOCEPTOR  AND  COMPLEMENT  145 

the  bacteria  or  their  poisonous  constituents  to  the  cell.  It  differs 
from  the  antitoxin,  however,  in  that  it  has  two  affinities,  one 
for  the  complement  and  the  other  for  the  bacterial  substance. 
On  account  of  the  existence  of  the  two  affinities  it  is  called  an 
amboeeptor.  Some  serums  contain  such  amboceptors  for  certain 
bacteria  without  previous  immunization,  hence  the  term  immune 
body  is  reserved  for  amboceptors  developed  by  immunization. 

Amboeeptor  and  Complement. — The  function  of  the 
amboeeptor  is  to  unite  the  bacterial  protoplasm,  to  which  it  is 
attached  by  one  affinity,  to  the  complement  which  it  holds  by 
its  other  affinity,  or,  to  put  it  in  a  more  strictly  chemical  way, 
the  addition  of  the  amboceptors  to  the  bacteria  gives  them  a 
chemical  affinity  for  complement.  It  is,  therefore,  an  inter- 
mediary body,  uniting  the  complement  to  the  bacterial  protoplasm. 
The  complement  is  the  substance  that  actually  destroys  the  bac- 
teria, in  which  respect,  as  well  as  in  its  susceptibility  to  heat,  it 
resembles  the  enzymes.  Complement  is  present  in  normal 
serums,  and,  as  it  is  not  increased  in  amount  during  immuniza- 
tion, it  may  not  be  sufficient  to  satisfy  all  the  amboceptors,  hence 
it  may  be  impossible  to  secure  marked  bactericidal  effects  even 
when  many  amboceptors  have  been  formed.  If  the  comple- 
ment in  an  immune  serum  has  been  destroyed  by  heating,  it 
may  be  replaced  by  adding  normal  serum  from  another  animal, 
even  of  some  other  species  ;  indicating  either  that  the  complement 
is  not  absolutely  specific  in  its  nature,  or  that  quite  the  same  com- 
plement may  be  present  in  the  blood  of  many  different  animals. 
The  origin  of  the  complement  is  unknown,  but  it  has  been  urged 
that  the  leucocytes  are  an  important  source  of  this  substance, 
if  not  its  chief  one ;  there  is  evidence,  however,  that  various 
organs  and  cells  may  also  produce  complement.  Its  most 
prominent  characteristics  are  its  extreme  susceptibility  to  heat, 
and  the  resemblance  of  its  action  to  the  action  of  enzymes.1 
Hektoen 2  found  that  it  could  be  made  to  unite  with  Mg,  Ca, 
Ba,  Sr,  and  SO4  ions,  which  rendered  the  complement  (for 
typhoid  bacilli  and  red  corpuscles)  inactive.  Man  waring 3  found 
that  these  ions  could  be  separated  again  from  the  complement 
by  simple  chemical  precipitation. 

According  to  the  Ehrlich  theory,  complement,  like  toxins 
and  enzymes,  possesses  at  least  two  groups  :  one,  the  hapto- 
phore,  with  which  it  unites  with  the  amboeeptor ;  the  other,  the 
toxophore  (or  zymophore,  because  of  its  enzyme-like  action),which 

1  See  Walker,  Jour,  of  Physiol.,  1906  (33),  p.  xxi. 
a  Trans.  Chicago  Path.  Soc.,  1903  (5),  303. 
3  Jour.  Infectious  Diseases,  1904  (1),  112. 

10 


146     CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 

attacks  the  bacterial  protoplasm.  It  may  degenerate  and  lose 
its  toxophore  group  while  retaining  the  power  to  combine  by- 
means  of  its  haptophore  group,  thus  forming  a  complementoid. 
Complement  and  amboceptor  exist  side  by  side  in  the  serum, 
not  uniting  with  one  another  until  the  amboceptor  has  become 
attached  to  the  bacterial  protoplasm. 

In  its  effect  of  dissolving  bacteria  (and  also  other  cells  against 
which  animals  may  have  been  immunized)  complement  resembles 
the  enzymes,  and  it  is  generally  looked  upon  as  related  to  them.1 
As  yet,  however,  none  of  the  products  of  proteolysis  has  been 
isolated  from  substances  acted  upon  by  complement,  nor  do  the 
changes  it  produces  resemble  those  produced  by  proteolytic 
enzymes  in  all  details.  In  particular,  complement  seems  to 
participate  in  reactions  according  to  the  law  of  definite  propor- 
tions, unlike  the  enzymes.2  The  chemical  nature  of  comple- 
ment seems  to  be  entirely  unknown.  In  certain  immune  reac- 
tions, colloids  (lecithin,  silicic  acid 3)  can  play  the  role  of  com- 
plement and  immune  body,  but  these  reactions  are  probably 
quite  different  from  those  of  bacteriolysis  by  immune  serum. 

Immune  body  (amboceptor)  is  formed,  according  to  Wasser- 
mann,  and  Pfeiffer  and  Marx,  in  the  spleen  and  hemopoietic 
organs,  since  in  immunization  it  can  be  demonstrated  in  these 
organs  before  it  appears  in  the  circulating  blood.  The  resistance 
of  immune  bodies  is  very  considerable  :  serum  prepared  in  1895 
by  Pfeiffer  against  cholera  vibrios  was  found  to  have  lost  almost 
none  of  its  activity  after  eight  years  in  an  ice-box  (Friedberger). 
Heating  twenty  hours  at  60°  scarcely  injures  them,  but  70°  for 
one  hour  destroys  them  almost  completely,  and  heating  the  serum 
to  100°  destroys  all  the  immune  bodies.  They  are  quite  resistant 
to  putrefaction,  and,  like  the  antitoxins,  do  not  dialyze. 

According  to  Pfeiffer  and  Proskauer,4  digestion  of  the  glob- 
ulin precipitate,  in  which  immune  bodies  are  carried  down, 
does  not  destroy  their  activity  completely  even  when  all  the 
proteids  are  thus  removed.  Removal  of  the  nucleo-albumin  or 

1  The  suggestion  has  been  made  that  bacteriolysis,  even  in  immune  serum, 
depends  upon  osmotic  disturbances.    Lootz  and  Tallant  (Johns  Hopkins  Hosp. 
Bull.,  1900  (11),  220)  tested  the  electrical  conductivity  of  the  serum  before 
and  after  heating  to  57°,  and  found  no  change,  speaking  strongly  against  this 
rather  poorly  based  hypothesis.     Leuchs  (Arch.  f.  Hyg.,  1905  (54),  396)  also 
failed  to  find  evidence  that  bacteriolysis  by  immune  serum  is  due  to  osmotic 
changes.     As  regards  the  resemblance  of  bacteriolysis  to  proteolysis,  see  Turro, 
Berl.  klin.  Woch.,  1903  (40),  821. 

2  See  Liebermann,  Deut.  med.  Woch.,  1906  (32),  249. 

3  Landsteiner  and  Jagic,  Wien.  klin.  Woch.,  1904  (17),  63 ;  Munch,  med. 
Woch.,  1904  (51),  1185. 

4  Cent.  f.  Bakt,,  1896  (19),  191. 


IMMUNITY  AGAINST  BACTERIAL   CELLS  147 

nuclein  does  not  remove  the  immune  bodies  from  the  serum. 
Immune  serum  kept  three  months  in  alcohol  yielded  an  extract 
with  distilled  water  that  was  rich  in  immune  bodies,  but  almost 
free  from  proteid.  Pick,  Rhodain,  and  Fuhrmann  found  that 
immune  bodies  are  precipitated  entirely  in  the  euglobulin  frac- 
tion of  the  serum  proteids.  From  these  experiments  it  seems 
probable  that  the  immune  body  is  not  itself  a  proteid,  although 
closely  associated  with  the  serum  globulins.1 

Opsonin.2 — Bactericidal  substances  are  not  so  readily  pro- 
duced for  all  bacterial  organisms  as  they  are  for  typhoid  bacilli, 
cholera  spirilla,  etc.,  particularly  not  for  the  pus  cocci,  B.  anthra- 
cis,  and  B.  tuberculosis.  In  defending  the  body  against  these 
organisms  it  would  seem  that  phagocytosis  by  leucocytes  is 
an  important  process,  but  in  just  what  the  difference  lies 
between  immunized  and  normal  animals  was  formerly  not  clear. 
It  now  seems  to  have  been  established,  particularly  by  the 
work  of  Wright  and  Douglas,3  that  phagocytosis  depends 
upon  the  presence  of  certain  substances  in  the  plasma,  which 
they  call  opsonins.  Not  until  bacteria  have  been  acted  upon 
by  the  opsonin  can  they  be  taken  up  by  the  phagocytes. 
Opsonin  exists  in  the  normal  blood  of  many  animals,  and  can 
be  increased  by  immunization,  and  the  opsonin  of  one  species 
of  animal  can  sensitize  bacteria  for  the  phagocytes  of  another 
species.  It  resembles  toxin  and  complement  in  having  a  hapto- 
phore  group  to  combine  with  the  bacteria,  and  an  opsoniferous 
group  susceptible  to  heat  of  60°-65°  ;  when  thus  heated,  the 
opsonin  is  converted  into  an  opsonoid.  Nothing  is  yet  known 
concerning  the  change  brought  about  in  the  bacteria  by  the 
opsonin,  although  it  has  been  established  that  it  is  the  bacteria 
that  are  modified  and  not  the  leucocytes.  The  chemical  nature 
of  the  opsonins  is  likewise  unknown,  except  that  they  may  com- 
bine with  certain  inorganic  ions  and  are  then  inert  (Hektoen 
and  Ruediger 4 ).  This  topic  is  discussed  further  in  connection 
with  phagocytosis. 

Antienzymes. — The  development  of  substances  inhibiting  the  action 
of  bacterial  enzymes  during  the  course  of  immunization  has  been  dis- 
cussed in  a  preceding  chapter  (under  "  Enzymes").  Their  importance 

1  Ascoli  found  that  the  active  substance  of  anthracidal  serum,  which  is  not 
an  amboceptor,  is  contained  in  the  pseudo-globulin  fraction  of  asses'  serum, 
but  in  goat's  serum  part  is  in  the  euglobulin  fraction.     (Biochem.  Centr.,  1906 
(5),  458.) 

2  Ke"sum6  and  literature  by  Hektoen,  Jour.  Amer.  Med.  Assoc.,  1906  (46), 
1407. 

3  Proc.  of  the  Koyal  Society,  1903  (72),  357;  1904  (73),  128. 

4  Jour.  Infectious  Diseases,  1905  (2),  129. 


148     CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 

in  defense  against  infection  is,  however,  questionable,  as  we  have  no 
evidence  that  the  bacterial  enzymes  cause  harm  to  the  infected  organ- 
ism, or  that  the  products  of  their  action  are  particularly  toxic.  By  pre- 
venting the  assimilation  of  food  by  the  bacteria,  however,  antienzymes 
might  inhibit  bacterial  growth,  a  possibility  that  seems  not  to  have 
been  investigated. 

AGGLUTININS  AND  AGGLUTINATION 

This  well-known  phenomenon,  the  clumping  or  agglutina- 
tion of  bacteria  when  acted  upon  by  the  serum  of  immunized  or 
infected  animals,  can  hardly  be  considered  as  a  means  of 
defense,  since  we  have  no  evidence  that  it  in  any  way  protects 
the  animal.  Agglutinated  bacteria  seem  not  to  be  severely 
injured  by  the  process,  and  can  grow  vigorously  in  agglutina- 
tive serum.  Possibly  agglutination  favors  phagocytosis  and 
lessens  dissemination  of  the  infecting  organisms,  but  it  is 
improbable  that  the  influence  on  the  course  of  infection  is  great. 
Agglutination,  therefore,  may  be  looked  upon  as  an  incident  in 
the  infection,  rather  than  as  a  definite  method  of  resistance. 

For  the  production  of  agglutination  it  is  necessary  that  the 
bacterial  body  contain  a  substance  (ctgglutinogeri)  which  has 
an  affinity  for  the  specific  constituent  of  the  serum,  agglutinin. 
Normal  serum  may  contain  agglutinin  ;  e.  </.,  typhoid  bacilli 
are  sometimes  agglutinated  by  normal  serum,  even  when  it  is 
diluted  thirty  times,  but  by  immunization  this  property  can  be 
greatly  increased  until  agglutination  may  be  obtained  with  dilu- 
tions as  high  as  one  to  a  million.  In  immunization  it  is 
believed  that  the  agglutinogen,  which  is  probably  an  intracellu- 
lar  constituent  of  the  bacteria,  acts  as  a  stimulator  to  the  for- 
mation of  the  specific  agglutinin.  Hence,  when  we  inject 
extracts  of  cells  containing  endotoxins,  we  secure  agglutinins, 
for  the  agglutinogens  are  liberated  from  the  cells  under  the 
same  conditions  as  the  endotoxins. 

We  can  obtain  agglutinins  against  nearly  all  bacteria,  includ- 
ing non-pathogenic  forms,  but  in  varying  strengths.  Agglutinins 
are  found  in  the  blood  stream  in  the  highest  concentration,  but 
they  are  also  present  in  the  various  organs  and  in  the  milk. 
The  place  of  their  formation  is  unknown.  Since  bacteria  con- 
tained within  a  collodion  sac  implanted  in  an  animal  give  rise  to 
the  production  of  agglutinins,  it  is  evident  that  the  agglutino- 
gens are  diffusible  to  some  extent,  at  least,  through  collodion. 
Old  cultures  of  bacteria  contain  free  agglutinogens,  probably  lib- 
erated from  disintegrated  cells,  and  filtrates  of  such  cultures  will 
neutralize  agglutinins,  showing  both  that  the  agglutinogens  are 
filterable,  and  that  the  reaction  of  agglutination  is  a  chemical 


AGGLUTININS  AND  AGGLUTINATION  149 

one  and  not  dependent  upon  the  presence  of  cells.  Agglutino- 
gens  are  said  to  pass  through  dialyzing  membranes,  while  agglu- 
tinins  do  not. 

Properties  of  Agglutinins. — Like  most  of  the  other 
substances  produced  in  immunity,  agglutinins  are  precipitated 
out  of  the  serum  in  the  globulin  fraction  (see  Pick's  table, 
p.  140).  All  attempts  to  separate  them  from  proteids  have 
been  unsuccessful.  Stark l  found  that  trypsin  does  not  attack 
the  agglutinins  readily,  corresponding  to  the  resistance  of  the 
serum  proteids  to  this  enzyme ;  alkaline  papayotin  solution 
destroys  them  slowly,  while  pepsin  acts  much  more  rapidly. 
Alkalies  are  destructive  even  when  quite  dilute,  while  acids 
are  much  less  harmful.  The  temperature  resistance  of  agglu- 
tinins seems  to  be  variable,  plague  agglutinin  being  destroyed  at 
56°,  while  purified  typhoid  agglutinin  may  resist  80°-90°  ; 
most  agglutinin  serums  lose  their  property  at  60°— 65°.  The 
rate  of  reaction  of  agglutinins  increases  with  the  temperature, 
as  long  as  this  is  not  high  enough  to  injure  the  reacting  sub- 
stances.2 

The  structure  of  the  agglutinins  (in  the  Ehrlich  theory)  is  sim- 
ilar to  that  of  the  toxin  ;  i.  e.,  there  is  a  haptophore  group  by 
which  they  combine  with  the  agglutinogen,  and  a  toxophore 
group  by  which  they  produce  the  changes  that  cause  agglutina- 
tion. The  agglutinogen  is  probably  related  to  the  antitoxins  in 
structure,  having  a  single  haptophore  to  unite  with  the  agglu- 
tinin. By  degeneration  of  the  toxophorous  group  of  the 
agglutiniu,  agglutinoids  may  be  formed.  It  is  believed  that 
agglutinins  are  cell  receptors,  which  have  a  group  with  a  chem- 
ical affinity  for  the  agglutinogen  of  the  bacterial  protoplasm, 
and  also  another  group  which  brings  about  the  agglutination. 
They  are,  therefore,  more  complex  than  the  simple  receptors 
that  unite  with  toxins,  and  are  called  receptors  of  the  second 
order. 

Just  what  constituent  of  the  bacteria  acts  as  the  stimulus  to 
the  production  of  the  agglutinin  is  unknown.  Apparently, 
there  are  at  least  two  bacterial  substances  with  this  property, 
one  of  which  seems  not  to  be  a  proteid,  since  it  is  soluble  in 
alcohol  and  gives  no  biuret  reaction,  and  resists  temperature  up 
to  165°.  The  other  gives  all  proteid  reactions,  and  is  destroyed 
by  heating  to  62°.  We  consider,  therefore,  that  there  are  two 
agglutinogens  in  the  bacterial  cell,  one,  thermostable,  the  other, 
thermolabile.  The  difference  in  the  function  of  these  two 

1  Inaug.  Dissert.,  Wurzburg,  1905. 

2  Madsen,  et  al.,  Jour.  Exper.  Med.,  1906  (8),  337. 


150     CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 

agglutinogens  is  still  a  matter  of  dispute.1  Likewise,  the  ques- 
tioD  as  to  whether  they  occur  in  the  membrane  or  within  the 
bacterial  cell  is  still  open,  but  Craw 2  found  that  the  insoluble 
residue  of  crushed  typhoid  bacilli,  after  being  washed  free  of  all 
soluble  constituents,  was  but  slightly  agglutinated  by  active 
serum  ;  therefore,  the  agglutinogeus  are  probably  soluble  intra- 
cellular  substances. 

Agglutinated  bacteria  can  be  again  separated  from  one 
another  by  the  action  of  organic  and  inorganic  acids,  alkalies, 
acid  salts,  and  by  heating  to  70°  or  75°,  and  after  once  being  sep- 
arated they  cannot  be  reagglutinated  by  fresh  serum.3 

The  Mechanism  of  Agglutination. — This  has  been  a 
fruitful  field  of  research,  in  which  the  application  of  physical 
chemistry  has  been  very  profitable.  At  first  it  was  believed 
that  the  clumping  was  brought  about  by  loss  of  motility,  until 
it  was  found  that  non-motile  bacilli  were  equally  affected.  Sim- 
ilarly, the  hypothesis  of  adhesion  of  the  flagellse  was  disposed 
of.  Gruber 4  and  others  supposed  that  a  sticky  substance,  "  glab- 
rificin,"  was  absorbed  from  the  serum  by  the  bacilli,  which 
caused  them  to  adhere  on  contact  with  one  another ;  but  this 
does  not  explain  the  nocking  together  of  non-motile  bacilli. 
Paltauf  considered  that  the  specific  precipitin  (see  next  section) 
produced  by  immunization  carried  the  bacilli  down  in  the  pre- 
cipitate formed,  and  there  is  reason  to  believe  that  this  reaction 
is  of  importance,  but  it  does  not  explain  all  the  facts  of  agglu- 
tination, nor  is  the  relation  between  agglutinating  and  precipi- 
tating power  of  immune  serums  a  constant  one.  Neisser  and 
Friedmann  5  found  that  if  the  bacterial  cells  were  saturated  with 
lead  acetate,  washed  in  water  until  all  soluble  lead  was  removed, 
and  then  treated  with  H2S,  they  were  promptly  agglutinated 
and  precipitated,  supporting  other  observations  that  indicate 
that  precipitation  within  the  bacterial  cells  can  lead  to  agglu- 
tination. This  sort  of  agglutination  is  probably  related  to  the 
process  of  formation  of  coarse  flocculi  in  solutions,  and  probably 
depends  upon  alterations  in  surface  tension. 

Bordet6  made  the  important  observation  that  agglutination 
would  not  occur  if  both  the  bacterial  suspension  and  the  agglu- 
tinating serum  were  dialyzed  free  from  salts  before  mixing  ;  but 
if,  to  such  mixtures,  a  small  amount  of  NaCl  was  added,  agglu- 

1  See  Paltauf,  Kolle  and  Wassermann's  Handbuch,  Bd.  4,  p.  726. 

2  Loc.  cit. ,  infra. 

3Eisenberg  and  Volk,  Zeit.  f.  Infektionskr.,  1902  (40),  192. 

4  For  complete  bibliography,  see  Craw.  Jour,  of  Hygiene,  1905  (5),  113. 

5  Munch,  med.  Woch.,  1904  (51),  465  and  827. 

6  Ann.  d.  1'  Inst.  Pasteur,  1899  (13),  225. 


AGGLUTININS  AND  AGGLUTINATION  151 

ti nation  and  precipitation  of  the  bacteria  occurred  at  once. 
This  observation  brought  the  phenomenon  of  bacterial  agglu- 
tination into  close  relation  with  the  precipitation  of  colloids  by 
electrolytes,  Bordet  comparing  it  to  the  precipitation  of  par- 
ticles of  inorganic  matter  suspended  in  the  fresh  water  of  rivers 
that  occurs  when  the  fresh  water  meets  the  salt  water  of  the 
ocean.  He  found  that  the  agglutinin  combined  with  the  bac- 
teria in  the  absence  of  the  salts,  and  the  resulting  compound  was 
precipitated  by  the  addition  of  minute  amounts  of  electrolytes, 
which  did  not  precipitate  or  agglutinate  the  bacteria  or  the 
serum  alone.  This  indicates  that  the  agglutinins  cause  a  change 
in  the  bacteria  which  brings  them  under  the  same  physical  laws 
as  the  inorganic  colloidal  suspensions,  which  are  characterized 
by  being  precipitated  by  the  addition  of  traces  of  electrolytes.1 
This  precipitation  is  undoubtedly  due  to  changes  in  solution 
tension  and  surface  tension  (see  "  Precipitation  of  Colloids," 
introductory  chapter).  Before  the  agglutinin  combines  with 
the  bacteria  they  behave  like  the  colloidal  solutions  of  organic 
colloids,  being  only  precipitated  by  the  salts  of  heavy  metals, 
alcohol,  formalin,  etc.,  or  by  great  concentrations  of  neutral 
salts. 

According  to  Bechhold 2  normal  bacteria  behave  like  inorganic 
suspensions  that  have  each  particle  protected  by  an  albumin-like 
membrane,  which  prevents  them  from  being  thrown  out  of 
suspension  by  solutions  of  alkali  salts,  etc.  After  being  acted 
on  by  agglutinin  they  are  so  altered  that  they  behave  like  the 
unprotected  inorganic  suspensions,  and  are  precipitated  by  salts 
and  other  electrolytes.  This  suggests  the  possibility  that  the 
agglutinin  makes  the  bacteria  permeable  for  these  electrolytes. 
Agglutination  obeys  the  same  laws  as  other  similar  physical 
phenomena ;  the  rate  of  agglutination  depends  upon  the  con- 
centration of  the  suspension  and  of  the  electrolytes,  and  varies 
with  the  valence  of  the  cations.  Although  bacteria  in  an  elec- 
tric stream  move  toward  the  anode  like  all  suspensions,  after 
being  acted  on  by  agglutinin  they  are  agglutinated  by  the 
current  between  the  poles  ;  this  indicates  the  importance  of  the 
electrical  charges  of  the  bacterial  surfaces  in  their  agglutination 
reactions. 

In  all  respects  the  behavior  of  bacteria  and  agglutinin 
resembles  the  behavior  of  colloidal  mixtures  in  suspension 

1  Arrhenius  (Zeit.  physikal.  Chem.,  1903  (46),  415)  has  attempted  to  show 
that  the  gas  laws  are  applicable  to  the  partition  of  agglutinin  between  the 
bacteria  and  the  medium,  which  he  compares  to  the  partition  of  iodin  between 
water  and  carbon  disulphid.     This  idea  is  not  accepted  by  Craw  (loc.  cit.). 

2  Zeit.  f.  physikal.  Chem.,  1904  (48),  385. 


152     CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 

(Neisser  and  Friedmann l )  which  form  an  electrically  amphoteric 
colloidal  suspension,  so  that  the  ions  of  electrolytes  or  the 
electric  currents,  by  discharging  them  unequally,  cause  precipita- 
tion. Physico-chemical  researches,  however,  have  yet  failed 
to  explain  the  specific  character  of  the  agglutinins  for  specific 
bacteria. 

PRECIPITINS2 

If  to  the  filtrate  from  a  bacterial  culture  we  add  in  proper 
proportions  the  serum  of  an  animal  immunized  against  the  same 
variety  of  bacteria,  or  against  their  cell  contents,  a  precipitate 
will  soon  form.  This  reaction  is  specific  in  that  it  is  produced 
to  a  much  less  degree,  or  not  at  all,  with  cultures  of  bacteria 
different  from  the  variety  used  in  immunization.  The  precipi- 
tated substances  seem  to  consist  of  the  soluble  proteid  con- 
stituents of  the  filtrate  derived  from  the  bacterial  cells. 

This  reaction  seems  to  be  of  little  significance  as  a  means  of 
defense  against  bacterial  invasion  ;  but  the  discovery  that  all 
forms  of  proteids  when  injected  into  animals  may  cause  the 
appearance  of  specific  precipitating  substances  in  the  serum  of 
the  animals,  has  led  to  most  important  applications  of  the  pre- 
cipitation reaction.  Apparently  every  variety  of  proteid  is  in 
a  certain  sense  poisonous  to  animals  that  do  not  normally  have 
it  in  their  blood  or  tissues,  and  its  injection  leads  to  a  reaction 
on  the  part  of  the  animal,  which  reaction  is  shown  by  symptoms 
of  sickness  and  the  appearance  of  the  specific  precipitating 
substances  in  the  serum.  It  is  the  sharp  limits  of  specificity 
that  render  the  precipitin  reaction  of  such  importance,  for  if  we 
immunize  an  animal  with  globulin  from  the  blood  of  a  horse,  its 
serum  will  precipitate  only  globulin  from  horse  blood,  and  not 
globulin  from  the  blood  of  a  dog,  or  man,  or  any  other  animal. 
Similarly,  if  the  immunization  is  with  cow's  milk,  the  serum  will 
precipitate  only  cow's  milk  and  not  the  milk  of  the  goat  or 
mare.  These  serum  reactions  are  of  importance  to  the  physio- 
logical chemist,  therefore,  since  they  furnish  a  means  of  distin- 
guishing between  closely  related  forms  of  proteids,  more  delicate 
by  far  than  any  known  chemical  reagent.  They  also  prove  that 
there  are  essential  chemical  differences  between  the  proteids  of 

1  Loc.  cit. ;  see  also  Girard-Mangin  and  Henri,  Compt,  Kend.  Soc.  Biol..  1904, 
vol.  56  ;  and  Zangger,  Cent.  f.  Bakt.  (ref.),  1905  (36),  225. 

2  For  complete  bibliography  of  the  subject  of  "  Precipitins"  see  the  resume 
by  Michaelis,  Biochemisches " Centralblatt,  1905  (3),  693;  and  Zeit.   f.  klin. 
Med.,  1905  (56), 409  ;  Blum,  Cent.  allg.  Path.,  1906  (17),  81 ;  Pfeiffer,  Arch.  f. 
Kriminalanthropol.,  1906,  Bd.   22.      For  methods  and  earlier  literature  see 
Nuttall,  Jour,  of  Hygiene,  1901  (1),  367. 


PRECIP1TIXS  153 

different  species  of  animals,  even  when  by  all  other  methods 
these  proteids  seem  to  be  practically  identical ;  e.  </.,  lactalbumin 
of  cow's  milk  is  in  some  respect  different  from  lactalbumin  of 
goat's  milk  since  it  produces  a  different  precipitin.  To  the 
physiologist  they  indicate  the  method  adopted  by  the  body  to 
guard  itself  against  invasion  by  foreign  proteids  introduced  in 
the  food,  and  show  the  importance  of  the  complicated  digestive 
and  assimilative  mechanism  of  the  alimentary  tract  in  securing 
complete  destruction  of  the  specific  characters  of  all  proteid  foods 
before  they  enter  the  blood.  Clinically  they  offer  a  means  of 
detecting  abnormal  permeability  of  the  walls  of  the  digestive 
tract,  and  possibly  a  means  of  determining  the  source  of  proteids 
found  in  the  urine.  Medicolegally  they  offer  an  accurate  method 
of  determining  the  origin  of  blood  and  serum  stains,  no  matter 
how  old  the  stain  may  be;  thus  Hansemann l  found  that 
material  obtained  from  a  mummy  5000  years  old  gave  the 
precipitin  reaction. 

Production  of  Precipitins. — For  the  production  of  the 
precipitation  reaction  it  is  necessary  to  have  in  the  substance 
used  for  immunization  a  certain  group,  the  precipitogen,  which, 
when  injected  gives  rise  to  production  of  precipitin  by  the 
animal.2  Apparently  any  proteid  may  act  as  a  precipitogen 
if  injected  into  the  proper  animal,  but  it  must  be  a  foreign 
proteid;  rabbit  serum  will  not  produce  precipitins  if  injected 
into  a  rabbit,3  probably  because  it  is  normally  present  in  the 
blood  of  the  rabbit  and  therefore  does  not  stimulate  any 
reaction.  In  general  the  more  foreign  the  proteid,  the  greater  the 
amount  of  precipitin  ;  closely  related  animals,  e.  g.,  rabbit  and 
guinea-pig,  produce  little  precipitin  for  one  another's  proteids. 
This  indicates  distinctly  that  difference  in  species  depends  upon 
or  is  associated  with  difference  in  chemical  composition  of  the 
proteids.  Only  proteids  can  produce  precipitins ;  when  split 
to  the  peptone  stage  they  lose  this  property.  No  precipitins 
can  be  secured  against  the  other  food-stuffs  ;  i.  e.,  carbohydrates 
and  fats.  Possibly  precipitins  can  be  produced  for  closely 
related  substances  with  molecules  approximating  in  size  the 
proteid  molecule,  e.  g.,  certain  substances  present  in  proteid-free 
filtrates  of  bacterial  cultures. 

Since  precipitation  of  colloids  is  accompanied  by  or  dependent 

1  Munch,  med.  Woch.,  1904  (30),  572. 

2  Krausand  Schiffmann  (Wien.  klin,  Woch.,  1905  (18),  1033)  believe  that 
precipitins  as  well  as  agglutinins  are  formed  in  the  circulating  blood>  not  in 
the  organs. 

3  Rarely  a  slight  reaction  against  homologous  proteids  has  been  obtained 
(iso-precipitins). 


154     CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 

upon  aii  aggregation  of  their  particles,  the  precipitin  reaction 
is  closely  related  to  the  agglutination  reaction.  The  amount 
of  precipitation  obtained  is  much  modified  by  the  amount  of 
inorganic  salts  present,  and,  according  to  Friedmann,1  there  is  a 
general  resemblance  between  the  precipitin  reactions  and  the 
precipitations  occurring  when  colloids  precipitate  one  another  ; 
i.  e.,  when  an  amphoteric  colloid  reacts  with  either  an  acid  or  a 
basic  colloid.  Possibly  the  constituents  of  the  nucleoproteids 
furnish  the  acid  and  basic  colloids  for  these  reactions.  2  As 
mentioned  in  the  preceding  section,  agglutination  of  bacteria  is 
independent  of  the  precipitins,  although  very  probably  influenced 
by  them.  As  with  all  the  other  substances  of  this  class,  the 
precipitins  have  a  haptophore  group  by  which  they  unite  to  the 
proteid  molecule,  and  another  group  by  which  they  produce  the 
change  resulting  in  precipitation.  When  the  latter  group  is 
destroyed  by  heating  to  60  °,  the  precipitin  is  converted  into  a 
precipitoid. 

According  to  the  source  of  the  proteid  used  we  recognize 
bacterial  precipitins,  pJiyto-precipitins  (for  plant  proteids),  and 
zooprecipitins  (for  animal  proteids).  Although  tissue  extracts, 
body  fluids,  and  exudates  are  generally  used  in  immunizing, 
purified  constituents  of  these  proteid  mixtures  will  also  excite 
precipitin  formation,  e.  g.,  we  may  immunize  with  caseinogen  as 
well  as  with  milk.  Immunization  with  frequently  recrystallized 
albumins  is  less  successful  (Obermayer  and  Pick).  Complete 
pepsin  digestion  of  proteids  deprives  them  both  of  their  precipi- 
tability  and  their  power  to  produce  precipitins,  the  former 
property  being  lost  first.  Trypsin  seems  to  produce  the  same 
effect  more  slowly.  Heating  to  coagulation  —  indeed,  heating  in 
the  autoclave  —  does  not  destroy  the  precipitogenous  property  of 
proteids,  but  modifies  somewhat  the  character  of  the  precipitiu 
obtained.3 

As  proteids  introduced  into  the  stomach  are  normally  des- 
troyed before  being  absorbed,  they  do  not  enter  the  blood  and 
cause  precipitin  formation.  However,  as  is  well  known,  eating 
of  excessive  amounts  of  egg-albumen  or  other  easily  absorbed 
proteids  may  result  in  their  passing  the  barriers  and  entering 
the  blood  stream,  and  in  this  way  precipitins  have  been  experi- 


.  f.  Hyg.,  1906  (55),  361. 

2  See  Friedmann  and  Friedenthal,  Zeit.  exp.  Path.  u.  Ther.,  1906,  (3)  73. 

3  See  Obermayer  and  Pick,  who  consider  in  detail  the  effects  of  various 
modifications  of  proteids  upon  their  power  to  incite  precipitin  formation  (Wien. 
klin.  Woch.,  1906  (19),  327).     The  precipitability  of  the  serum,  or  its  power 
to  produce  precipitins,  is  not  affected  by  disease  (Pribram,  Zeit.  exp.  Path.  u. 
Ther.,  1906  (3),  28). 


PRECIPITINS  155 

mentally  produced.1  Presumably  the  precipitin  reaction  is  a 
means  of  throwing  such  foreign  proteids  out  of  solution  and 
rendering  them  harmless. 

Precipitin  appears  in  the  blood  generally  about  six  days  after 
injection  of  the  proteid,  but  disappears  after  injection  of  each 
subsequent  dose  of  proteid,  to  reappear  again  after  a  somewhat 
shorter  lapse  of  time.  After  injections  are  stopped,  the  precipi- 
tin disappears  rather  rapidly,  but  never  appears  in  the  urine, 
although  it  may  enter  the  fetal  blood  from  the  blood  of  preg- 
nant female  animals.  Leucocytosis,  both  local  and  general, 
follows  the  serum  injection,  and  it  has  been  suggested  that  the 
leucocytes  are  the  source  of  the  precipitin.  The  presence  of 
precipitins  in  the  blood  does  not  seem  to  prevent  the  excretion 
of  the  foreign  proteid  in  the  urine,  nor  are  the  animals  less 
susceptible  to  the  toxic  action  of  the  foreign  proteid  ;  indeed, 
the  reaction  is  even  stronger  in  the  immunized  animals,  and 
sometimes  the  ordinary  dose  becomes  fatal,2  as  mentioned  pre- 
viously under  "  Toxicity  of  Serum." 

Chemical  Properties. — In  its  chemical  nature  precipitin  re- 
sembles the  "antibodies"  generally,  being  precipitated  in  the 
euglobulin  fraction  of  the  serum,3  and  slowly  destroyed  by 
trypsin,  rapidly  by  pepsin.  It  cannot  be  separated  from  the 
serum  proteids. 

Specificity. — As  regards  the  specificity  of  precipitin  reactions 
certain  points  must  be  considered.  Precipitin  against  human 
albumin  reacts  with  human  globulin,  but  not  with  either  horse 
albumin  or  globulin.  The  groups  that  react,  therefore,  are 
characteristic  of  the  species,  but  common  to  different  proteids 
of  the  same  species.  This  group  does  not  occur  in  all  proteids, 
however,  even  in  the  same  species,  for  precipitins  against  cow's 
serum  do  not  react  with  cow's  milk.  Bacterial  precipitins 
react  frequently  with  members  of  an  entire  group.  For  ex- 
ample, serum  of  animals  immunized  against  B.  typliosus  may 
produce  precipitates  in  filtrates  from  cultures  of  numerous  other 
members  of  the  colon-typhoid  group,  although  quantitative 
differences  exist  in  favor  of  the  form  used  in  immunizing.4 
Likewise  precipitins  for  the  serum  of  one  animal  will  produce 

1  Concerning  the  toxicity  of  egg-albumen,  see  Sollmann  and  Brown,  Jour. 
Exp.  Med.,  1902  (6),  207. 

2  See  Rosenau  and  Anderson,  U.  S.  Gov't.  Dept.  of  Hygiene  Bull.,  No.  29, 
1906;  Jour.  Med.  Research,  1906  (15),  179. 

3Funck  (Cent.  f.  Bakt.  (ref.),  1905  (36),  744)  states  that  if  the  precipitin 
serum  is  very  strong,  part  of  the  precipitin  comes  down  in  the  pseudoglobulin. 

*  For  literature  on  Bacterial  Precipitins  see  Norris,  Jour,  of  Infectious  Dis- 
eases, 1904  (1),  463. 


156     CHEMISTRY  OF  IMMUNITY  AGAINST  BACTERIA 

precipitates  in  the  blood  of  related  animals ;  e.  </.,  immune 
serum  against  human  serum  will  cause  precipitates  in  the  serum 
of  the  higher  apes.  The  precipitin  reaction  is,  therefore,  only 
quantitatively  specific,  not  qualitatively. 

The  precipitin  reaction  occurs  only  outside  the  body  (Mich- 
aelis).  When  serum  precipitins  are  injected  directly  into  the 
blood,  no  precipitation  occurs,  but  merely  an  active  leucocytosis  ; 
if  injected  intraperitoneally,  there  is  local  leucocytosis.  Probably 
the  leucocytes  take  up  the  precipitate  as  fast  as  formed,  or  else 
the  absence  of  precipitate  depends  upon  the  fact  that  a  proper 
proportion  between  the  amount  of  precipitin  and  proteid  must 
exist,  an  excess  of  proteid  causing  a  resolution  of  the  precipi- 
tate. 

The  precipitation  by  precipitins  is  not  an  enzyme  action,  for 
the  precipitins  are  used  up  in  the  process.  It  apparently  does 
not  differ  from  precipitations  of  colloids  by  other  colloids  of 
opposite  electrical  charges,  except  in  that  the  reaction  is  specific. 


CHAPTER   VII 

CHEMICAL  MEANS  OF  DEFENSE  AGAINST 
POISONS  OF  KNOWN  COMPOSITION 

ALTHOUGH  the  examples  of  acquired  immunity  against  poisons 
of  known  chemical  composition  are  few  indeed,  nevertheless  the 
body  possesses  means  of  defense  against  many  such  poisons,  which 
decrease  to  greater  or  less  degree  their  harmful  effects.  True 
immunity,  associated  with  the  production  of  neutralizing  sub- 
stances in  the  blood,  has  as  yet  been  obtained  only  against  sub- 
stances of  proteid  nature  or  substances  very  closely  resembling 
the  proteid  s.  Studies  on  bacterial  immunity  and  allied  topics 
have  as  yet  shown  nothing  to  explain  the  acquirement  of  toler- 
ance to  morphine,  alcohol,  arsenic,  and  other  similar  poisons. 
A  few  observers  have  claimed  that  the  serum  of  animals 
immunized  to  morphine  will  neutralize  to  some  degree  the  toxic 
effects  of  morphine,  but  these  results  have  not  been  generally 
substantiated.1  Others  have  claimed  that  increased  oxidative 
powers  are  developed  under  the  stimulation  of  the  poison  which 
permits  of  its  more  rapid  destruction,  especially  in  the  liver,  but 
the  experimental  support  of  this  hypothesis  is  slight.  Still 
another  idea  is  that,  at  least  in  the  case  of  morphine,  decomposi- 
tion products  are  produced  and  accumulate  in  the  body  that 
neutralize  physiologically  to  some  extent  the  morphine  itself;  this 
hypothesis  can  scarcely  be  applied  to  arsenic  and  alcohol  tolerance.2 

It  is  possible,  also,  that  the  cell  constituents  with  which  the 
poisons  ordinarily  combine  are  produced  in  increased  amounts 
under  the  stimulus  of  the  poison,  just  as  they  are  in  the  case 
of  immunization  with  toxins,  with  the  difference  that  the  com- 
bining substances  are  not  thrown  off  into  the  blood.  For 
example,  it  has  been  claimed  that  arsenic  is  ordinarily  combined 
and  held  in  the  liver  by  a  nucleoproteid,  and  the  suggestion 
has  been  made  that  in  arsenic  habitues  this  nucleoproteid  is 
increased  in  amount.  Again,  saponin  seems  to  act  upon  the 
cholesterin  of  the  red  corpuscles,  and  Robert  observed  some 
resistance  to  the  action  of  saponin  exhibited  by  the  serum  of 

1  See  Morgenroth,  Berl.  klin.  Woch.,  1903  (40),  471. 

2  Concerning  immunity  against  morphine  see  Faust,  Arch.  exp.  Path.  u. 
Pharm.,  1900  (44),  217;  and  Cloetta,  ibid.,  1903  (50),  453. 

157 


158   CHEMICAL  MEANS  OF  DEFENSE  AGAINST  POISONS 

immunized  animals,  which  he  attributes  to  an  increased  amount 
of  cholesterin,  perhaps  liberated  by  the  corpuscles  decomposed 
by  the  injected  poison,  or  perhaps  produced  in  excess  by  the 
tissues.  Wohlgemuth  1  has  also  suggested  that  in  the  case  of 
poisoning  with  large  amounts  of  substances  which  combine  with 
glycuronic  acid  (e.  g.,  lysol),  excessive  quantities  of  this  sub- 
stance are  formed  by  the  cells  and  excreted  into  the  blood, 
where  they  neutralize  the  poisons  in  much  the  same  manner  as 
the  antitoxins  neutralize  toxins. 

But  besides  these  scanty  examples  of  tolerance  to  poisons  the 
body  possesses  a  number  of  methods  for  opposing  many  other 
poisons  with  more  or  less  success ;  and,  poisons  invariably  act- 
ing chemically,  the  defenses  are  in  turn  largely  chemical.  We 
have  elsewhere  referred  to  the  destructive  action  of  the  enzymes 
of  the  digestive  tract  upon  bacterial  and  similar  poisons ;  this 
means  of  defense  cannot  apply  to  ordinary  chemical  substances, 
because  of  their  non-pro teid  nature.  But  the  acidity  of  the  gas- 
tric juice,  the  alkalinity  of  the  bile  and  pancreatic  juice,  and  the 
precipitating  effect  of  the  hydrogen  sulphide  formed  in  intestinal 
putrefaction  are  all  factors  that  help  to  neutralize  or  prevent 
the  absorption  of  certain  poisons,  their  total  efficiency,  however, 
being  on  the  whole  very  slight.  After  absorption  of  a  poison  a 
large  series  of  chemical  reactions  and  physiological  processes  is 
brought  into  play,  and  there  are  few  poisons  indeed  whose  harm- 
ful influence  is  not  more  or  less  decreased  by  these  means. 
Robert 2  classifies  these  protective  processes  as  follows  : 

1.  Rapid  elimination,  either  before  absorption  by  means  of 
diarrhea  and  vomiting,  or  by  the  same  means  after  absorption 
in  case  the  poisons  are  excreted  into  the  digestive  tract  ( e.  g., 
morphine,  venoms,  antimony,  and  many  other  metals).     Many 
poisons  are  very  rapidly    eliminated    by  other  routes  (e.  g., 
anesthetics,  curare),  in  some  instances  causing  harm,  particularly 
to  the  eliminating  organ  (e.  g.,  kidneys  in  phenol  poisoning, 
intestines  in  riciii  poisoning).     The  routes  and  conditions  of 
elimination  of  poison  have  been  recently   fully  discussed  by 
Lewin.3 

2.  Deposition  and  Fixation  in  Single  Organs  or  Tissues. — 
In  this  respect  the  liver  is  especially  important,  probably  be- 
cause of  its  location  and  function  as  a  filter  for  all  the  blood 
coming  fresh  from  the  alimentary  tract.     The  manner  and  means 

1  Biochem.  Zeitschr.,  1906  (1),  134. 

2  "  Lehrbuch  der  Intoxikationen,"  Stuttgart,  1902. 

8Deut.  med.  Woch.,  1906  (32),  169;  see  also  Mendel  et  al.,  Amer.  Jour. 
Physiol.,  1904  (11),  5;  1906  (16),  147  and  152. 


INORGANIC  POISONS  159 

by  which  this  fixation  is  brought  about  are  unknown.  Accord- 
ing to  Slowtzoff1  arsenic  is  fixed  by  the  nucleus  in  a  very  firm 
combination ; 2  mercury  by  globulins  in  a  less  stable  combination ; 
copper  by  the  nucleins,  but  less  firmly  than  the  arsenic.  Other 
poisons,  chiefly  alkaloids,  are  probably  combined  with  bile  acids. 
Possibly  some  poisons  combine  with  glycogen.  These  corn- 
pounds  are  but  slowly  broken  up,  and  thus  the  poison  reaches 
the  more  susceptible  and  more  important  tissues  in  a  relatively 
diluted  condition.  The  bones  seem  to  hold  in  harmless  form  poi- 
sonous fluorides,  and  to  less  extent  arsenic,  barium,  and  tungsten, 
which  persist  in  the  bones  for  a  great  length  of  time.  Leucocytes 
are  possibly  important  binders  of  poisons,  perhaps  through 
combination  with  their  nucleins,3  but  storage  in  these  labile  cells 
is  necessarily  of  relatively  brief  duration.  Many  poisons  com- 
bine with  the  inorganic  constituents  of  the  tissues  ;  e.  g.,  barium 
and  various  aromatic  substances  with  SO4 ;  silver  with  Cl,  etc. 

3.  Combination  with  substances  formed  or  contained  in  the 
tissues ;  the  resulting  substance  being  less  toxic  than  the  poison 
alone.  This  method  will  be  considered  at  greater  length  in  connec- 
tion wTith  the  related,  often  associated,  method  of  defense ;  namely : 

4.  Chemical  alteration,  with  or  without   subsequent  com- 
bination with  other  substances,  by   such  means  as  oxidation, 
reduction,  hydrolysis,  and  neutralization. 

5.  Impaired  absorption  should  also  be  considered  as  a  means 
of  defense  against  poisons.     This  may  depend  upon  the  injury 
to  the  gastro-intestinal  tract  produced  either  by  the  poison  itself 
or  by  some  independent  pathological  condition.    Cloetta  considers 
impaired  absorption  important  in  acquired  immunity  to  arsenic 
(see  below)  and  it  may  also  modify  the  effects  of  other  poisons. 

The  chemical  reactions  employed  in  defense  against  simple 
chemical  poisons  have  been  particularly  considered  by  E. 
Fromm,4  whose  outline  is  here  partially  followed,  and  to  which 
the  reader  is  referred  for  bibliography. 

INORGANIC   POISONS 

Metallic  poisons,  such  as  lead,  silver,  mercury,  and  arsenic, 
are  made  insoluble,  particularly  by  forming  compounds  with 
proteids  in  the  alimentary  tract,  intestinal  walls,  blood,  or  internal 

1  Hofmeister's  Beitr.,  1901  (1),  281 ;  1902  (2),  307. 

2  Denied  by  Heffter  (Arch,  internal,  de  Pharmacodyn.,  1905  (15),  399), 
who  considers  it  more  a  physico-chemical  process. 

3Stessano,  Compt.  Eend.  Acad.  Sci.,  1900  (131),  72. 

4  "  Die  chemischen  Schutzmittel  des  Tierkorpers  bei  Vergiftungen,"  Strass- 
burg,  Karl  Triibner,  1903.  See  also  re'sume'  by  Ellinger,  Deut.  med.  Woch., 
1900  (26),  580. 


160  CHEMICAL  MEANS  OF  DEFENSE  AGAINST  POISONS 

organs  ;  also  by  forming  sulphides  with  the  H2S  of  the  intes- 
tinal contents.  According  to  Cloetta1  immunization  against 
arsenic  depends  entirely  upon  a  reduction  of  absorption  in  the 
intestine,  for  the  longer  arsenic  is  taken,  the  less  appears  in  the 
urine  and  the  more  appears  in  the  feces.  At  the  same  time  the 
resistance  to  arsenic  injected  subcutaneously  is  not  increased  at 
all,  and  no  increase  in  resistance  can  be  obtained  by  repeated 
subcutaneous  injections  of  sublethal  doses. 

Free  acids  and  alkalies  are  partly  neutralized  by  the  alkaline 
and  acid  contents  of  the  gastro-intestinal  tract,  partly  by  form- 
ing compounds  with  the  proteids,  and  partly  by  the  alkalies  and 
carbonic  acid  of  the  blood  stream.  (See  "  Acid  Intoxication," 
Chap,  xviii.)  Phosphorus  and  sulphides  are  oxidized  after 
absorption  into  phosphoric  and  sulphuric  acid,  which  are  in 
turn  neutralized  by  the  alkalinity  of  the  blood  and  tissues. 
Lillie 2  has  called  attention  to  the  close,  palisade  arrangement 
of  the  nuclei  of  the  epithelium  lining  the  alimentary  tract,  which 
makes  it  necessary  for  all  substances  absorbed  to  pass  through  the 
zone  of  their  active  oxidative  influence,  a  fact  undoubtedly  of 
great  importance  in  the  defense  of  the  body. 

Reduction  of  iodic  acid,  chloric  acid,  hypochlorous  acid,  and 
their  salts  occurs  in  the  body,  resulting  in  their  conversion  into 
the  much  less  toxic  iodides  and  chlorides.  Tellurium  com- 
pounds are  also  reduced  and  rendered  insoluble.  This  reaction 
occurs  to  some  extent  in  the  intestines ;  how  much  in  other 
organs  is  unknown. 

Methylation,  the  addition  of  CH3  groups,  is  observed  in 
poisoning  by  tellurium,  which  is  eliminated  in  the  breath  as 
methyl  telluride,  and  also  in  the  sweat  and  feces.3  Selenium, 
pyridine,  and  some  other  substances  also  combine  with  methane. 
The  source  of  the  methane  is  possibly  in  the  xanthin  molecule. 

Summary. — There  are,  therefore,  three  chief  reactions  used 
against  inorganic  poisons  in  the  body,  oxidation,  reduction,  and 
splitting  off  of  water ;  neutralization  of  acids  or  alkalies  and  the 
formation  of  albuminates  and  sulphides  being  included  under 
the  last  heading,  since  in  these  reactions  the  splitting  oifof 
water  is  an  essential  step. 

ORGANIC  POISONS 

In  the  case  of  organic  poisons  an  equally  small  number  of 
primary  reactions  is  employed  in  their  detoxication,  but  in 

1  Arch.  exp.  Path.  u.  Pharm.,  1906  (54),  196. 

2  Amer.  Jour.  Physiol.,  1902  (7),  412. 

3  See  Mead  and  Gies,  Amer.  Jour.  Physiol.,  1901  (5),  105. 


ORGANIC  POISONS  161 

more  complicated  manners  and  combinations  corresponding  with 
the  complexity  of  organic  compounds. 

Oxidation,  which  has  already  been  mentioned  as  a  means 
of  destruction  of  bacterial  toxins,  is  naturally  one  of  the  most 
effective  agents  in  the  destruction  of  simpler  organic  substances, 
since  the  ordinary  decomposition  of  all  organic  food-stuffs  is 
through  oxidation.  There  are  numbers  of  specific  examples  of 
the  conversion  of  a  poisonous  into  a  less  poisonous  or  non- 
poisonous  substance  by  oxidation.  All  acids  of  the  fatty  acid 
series  are  oxidized  vigorously  in  the  body,  eventually  into  CO2 
and  H2O  ;  and  occasionally  pathologically  produced  oxalic,  ace- 
tic, and  lactic  acids  are  destroyed  in  this  way.  Uric  acid  is 
oxidized  vigorously  by  many  organs,  as  are  other  members  of 
the  purin  series,  such  as  caffein  and  theobromin.  Presumably 
oxidation  of  organic  poisons  as  well  as  of  food-stuffs  is  brought 
about  by  the  oxidizing  enzymes  of  the  cells,  as  shown  by 
Ehrlich's  indophenol  reaetion,  which  consists  of  the  oxidation  of 
paraphenylene  diamine  and  a-naphthol,  with  a  resulting  syn- 
thesis. This  reaction  has  been  shown  by  Lillie  l  to  occur  prin- 
cipally in  and  about  the  cell  nuclei. 

Combination,  with  or  without  Preliminary  Oxida- 
tion. —  Oxidation  is  also  an  essential  preliminary  step  to  many 
of  the  protecting  combinations,  in  which  a  cell  constituent  is 
united  to  an  organic  poison.  The  most  important  of  these  com- 
bining substances  are  : 

1.  Sulphuric  Acid.  —  One  of  the  earliest  and  most  impor- 
tant observations  of  the  protective  action  of  sulphuric  acid  was 
made  by  Baumann  and  Herter,2  who  showed  that  phenol  is  elim- 
inated as  a  potassium  salt  of  the  sulphuric  acid  derivative,  as 
follows  : 

C6H5OH  +  HO  -  SO3K  =  QjH50  -  SO3K  +  H2O, 


a  reaction  that  has  been  of  much  practical  use  in  treating  phenol 
poisoning.  As  phenol  and  cresols  are  produced  constantly  in 
intestinal  decomposition,  this  reaction  is  undoubtedly  of  great 
service,  since  the  salt  formed  is  relatively  harmless.  Indol  and 
skatol  are  similarly  detoxicated  by  being  converted  into  corre- 
sponding salts,  but  only  after  a  preliminary  oxidation  into  in- 
doxyl  and  skatoxyl,  according  to  the  following  reaction  : 


, 
C6H4<         CH  +  O  =  C6H4X 


(indol)  (indoxyl) 

1  Loc.  cit.  *  Zeit.  physiol.  Chem.,  1877  (1),  247. 

11 


162   CHEMICAL  MEANS  OF  DEFENSE  AGAINST  POISONS 

C(OH)  C-0-SO.OK 

CjH/  >  CH  +  HO  -  S02OK  =  C6H,  <     JCS       +  H2O. 

XNH/  M 

(indoxyl)  (indican) 

A  host  of  other  aromatic  organic  substances  are  similarly  com- 
bined with  sulphuric  acid/  with  or  without  preliminary  oxida- 
tion, including  all  substances  resembling  phenol  or  which  through 
oxidation  are  changed  into  phenols,  such  as  cresol,  thymol, 
anilin,  naphthalin,  pyrogallol,  and  tannin.  By  this  means  a 
poisonous  substance  is  converted  into  a  relatively  harmless  one, 
which  is  readily  soluble  and  rapidly  eliminated. 

2.  Glycuronic  acid  occupies  the  same  position  as  sulphuric 
acid,  combining  particularly  with  naphthol,  thymol,  camphor, 
chloral  hydrate,  and  butyl  chloral.  Sometimes  a  substance  may 
appear  in  the  urine  combined  in  part  with  sulphuric,  in  part 
with  glycuronic  acid,  showing  the  similarity  of  their  function. 
Apparently  when  there  is  not  sufficient  sulphuric  acid  in  the 
body  to  combine  with  all  the  poison,  the  excess  unites  with  gly- 
curonic acid,2  although  combination  between  glycuronic  acid  and 
the  aromatic  substance  begins  to  occur  before  all  the  sulphuric 
acid  is  exhausted.3  Glycuronic  acid  represents  merely  a  first 
step  in  the  oxidation  of  glucose,  as  follows  : 

OHC -  (CHOH)4 -  CH2OH  +  O2  =  OHC -  (CHOH)4 -  COOH  +  H2O. 

(glucose)  (glycuronic  acid) 

This  oxidation  occurs  after  the  aldehyde  group  of  the  glucose 
has  been  combined  by  some  other  substance  ;  hence  the  aldehyde 
group  escapes  oxidation,  although  ordinarily  more  easily  oxidized 
than  the  alcohol  group. 

Just  as  with  the  addition  of  sulphuric  acid,  oxidation  may  be 
a  preliminary  step  to  the  addition  of  glycuronic  acid ;  e.  g., 
naphthalin  is  oxidized  into  a-naphthol,  before  uniting  to  gly- 
curonic acid,  as  follows : 

H    H 

/C  — Cx         H  H    H 

HC<  V— Ck  ,€— CN         OH 

\C  —  C(  >CH  +  0=HC/  NC—Cv 

H        XC-C/  XJ-CC  >CH 

H     H  H         \C  —  <y 

H     H 

(naphthalin)  (a-naphthol) 

1  See  Hammarsten's  Text-book  (fourth  American  ed.),  p.  542. 

2  See  Austin  and  Barron,  Boston  Med.  and  Surg.  Jour.,  1905  (152),  269. 
Wohlgemuth  has  observed  a  case  in  which  all  the  sulphuric  acid  of  the  urine 
was  in  organic  combination  (Berl.  klin.  Woch.,  1906  (43),  508). 

3  See  Salkowski,  Zeit.  physiol.  Chem.,  1904  (42),  230. 


ORGANIC  POISONS  163 

The  same  is  the  case  with  many  camphors  and  terpenes.  Re- 
duction may  be  the  preliminary  step,  as  with  chloral  hydrate, 
which  is  first  reduced  to  trichlor-ethyl-alcohol.  In  still  other 
cases  splitting  off  of  water  is  the  chief  preliminary  step. 

3.  Glycocoll  is  one  of  the  earliest  known  combining  sub- 
stances, the  observation  of  the  combination  of  glycocoll  with 
benzoic  acid  to  form  hippuric  acid  being  the  first  proof  of  syn- 
thesis in  the  animal  body  discovered  by  Wohler  (1824).     The 
reaction  is  as  follows  : 

C6H5COOH  +  H2N  -  CH2  -  COOH  =  C6H5CO  —  HN  -  CH2  -  COOH. 

(benzoic  acid)  (glycocoll)  (hippuric  acid) 

A  special  enzyme  has  been  found  in  kidney  substance  which  can 
bring  about  this  reaction  outside  the  body.  Normally  this 
enzyme  occurs  chiefly  in  the  kidney  but  may  also  occur  in  other 
organs.  Many  other  aromatic  compounds  also  combine  with 
glycocoll  before  elimination,  e.  g.,  salicylic  acid.  Some  are  first 
altered  to  a  suitable  form  by  oxidation ;  e.  g.,  toluol  is  oxidized 
to  benzoic  acid,  xylol  to  toluic  acid,  nitro-benzaldehyde  to  nitro- 
benzoic  acid.  Many  of  the  substances  that  can  be  made  to 
combine  with  glycocoll  in  the  body  are  of  such  a  foreign  nature 
that  they  never  could  need  neutralization  under  any  other  than 
experimental  conditions,  but  here,  as  with  the  sulphuric  and 
glycuronic  acid  reactions,  combination  occurs  whenever  a  suit- 
able substance  is  present  in  the  blood,  glycocoll  always  being 
abundant  as  a  cleavage  product  of  the  proteids. 

4.  Urea  may  also  be  a  means  of  defense,  forming  salts  with 
organic  acids  which  are  rapidly  eliminated ;  e.  g.,  amido-benzoic 
acid  and  nitro-hippuric  acid. 

5.  Methane. — Methylation,  which  occurs  also  with  tellurium, 
is  observed  on  administration  of  pyridin,  as  shown  by  the  fol- 
lowing equation  : 

H     H  H    H 

X.C-CL  ^°-c^     /CH3 

HCf          >N  +  CH4  +  O  =  HOT  >N< 

\C-:C/  XJ=(/    XOH 

H     H  H     H 

(pyridin) 

This  reaction  is  of  special  importance,  because  many  alkaloids 
contain  a  pyridin  group;  and  the  resulting  methyl  compound 
may  be  less  toxic  than  the  original  alkaloid — e.  g.,  methyl  mor- 
phine. 

6.  Sulphur  split  off  from  proteids  may  combine  with  CNH 
and  CNK,  converting  them  into  the  much  less  toxic  sulpho- 
cyanides.1 

1  See  Meurice,  Arch.  int.  Pharmacodyn.,  1900  (7),  11. 


164   CHEMICAL  MEANS  OF  DEFENSE  AGAINST  POISOXS 

7.  Bile  Acids.  —  All  the  above-mentioned  reactions  are  pro- 
tective largely  because  the  substances  formed  are  soluble  and 
rapidly  eliminated,  as  well  as  being  less  toxic  than  the  original 
poison.  Compounds  of  many  poisons  are  formed  with  bile 
acids  which  are  insoluble,  and  therefore  only  slowly  dissolve  or 
decompose,  thus  protecting  the  body  from  overwhelming  doses 
of  the  poison.  Such  compounds  are  formed,  not  only  with 
inorganic  poisons,  but  also  with  alkaloids,  especially  strychnin, 
brucin,  and  quinin.  They  are  then  deposited  in  the  liver,  to  be 
slowly  dissolved  and  eliminated. 

Occasionally  acetic  acid  and  cystein  have  been  observed  to 
act  as  combining  substances. 

Neutralization  of  organic  acids  entering  the  body  or  formed 
in  metabolism  is  accomplished  by  the  sodium  carbonate  of  the 
blood  when  in  small  amounts  ;  if  excessive  in  quantity  (e.  g., 
diabetic  coma),  a  portion  is  combined  with  ammonia  and  appears 
as  an  ammonium  salt  in  the  urine.  Magnesium  and  calcium 
salts  may  also  help  in  the  neutralization,  probably  at  the 
expense  of  the  bone  tissue.1  (See  "  Acid  Intoxication,"  Chap. 
xviii.) 

Dehydration,  which  plays  a  prominent  part  in  a  number 
of  the  above-mentioned  syntheses,  is  particularly  important  in 
the  change  of  ammonium  carbonate  into  urea  : 


4—  (X  2V 

\CO  ==         >CO  +  2H20. 
4—  <y 


As  ammonium  salts  of  all  sorts  are  very  toxic,  especially  hemo- 
lytic,  while  urea  is  not,  this  process  is  probably  one  of  the  most 
important  detoxicating  reactions  of  the  body  because  of  the 
great  amount  of  ammonium  compounds  that  is  constantly  being 
formed  in  nitrogenous  metabolism. 

Summary.  —  As  Fromm  points  out,  the  variety  of  reactions 
and  the  variety  of  defensive  substances  are  both  remarkably 
small  in  number.  The  reactions  are  :  oxidation  and  reduction, 
hydration  and  dehydration,  and  perhaps  simple  addition  (methyl- 
ation).  The  chief  known  protective  substances  are  the  alkalies 
of  the  blood,  proteids,  hydrogen  sulphide,  sulphuric  acid,  glyco- 
coll,  urea,  cystein,  bile  acids,  glycuronic  acid,  and  acetic  acid. 
All  these  substances  are  normally  present  in  the  body,  and  none 
of  them  is  specific  against  any  one  poison,  but  each  combines 
with  several  poisons.  This  last  fact  is  interesting  in  comparison 

1  In  this  connection  it  may  be  mentioned  that  the  bactericidal  power  of  the 
blood  is  increased  if  the  blood  is  more  alkaline,  decreased  if  it  is  less  alkaline, 
than  usual. 


ORGANIC  POISONS  165 

with  the  highly  specific  nature  of  the  immune  substances  against 
bacteria  and  their  products. 

As  far  as  we  know,  no  particular  increase  in  the  neutralizing 
substances  results  from  the  administration  of  inorganic  or  or- 
ganic poisons.  The  body  does  not  appear  to  produce  any 
excessive  amounts  of  sulphuric  acid  in  carbolic-acid  poisoning 
or  of  glycocoll  when  ben  zoic  acid  is  administered.  Both  sub- 
stances are  present  in  the  body  normally,  and  as  much  as  is 
available  combines  with  the  poison ;  if  there  is  not  enough,  the 
remaining  poison  combines  with  something  else,  or  goes  un- 
combined.  In  other  words,  the  neutralizing  substances  de- 
scribed above  do  not  appear  to  be  the  result  of  any  special 
adaptation  to  meet  a  pathological  condition.  They  are  present 
in  the  body  as  a  result  of  normal  metabolism  ;  they  have  an 
affinity  for  various  chemical  substances,  some  of  which  happen 
to  be  poisons ;  if  these  poisons  happen  to  enter  the  body,  they 
may  be  combined  and  neutralized  to  some  extent,  but,  as  a  rule, 
very  incompletely.  There  appears  to  be  no  elaborate  process 
of  defense  against  the  chemically  simple  poisons,  such  as  seems 
to  be  called  into  action  by  bacterial  infection,  and  hence  a  degree 
of  resistance  or  immunity  similar  to  that  present  after  an  attack 
of  scarlet  fever  or  small-pox  does  not  exist  for  strychnin  or 
phosphorus. 


CHAPTEK    VIII 
PHYTOTOXINS  AND  ZOOTOXINS 

THE  production  of  substances  possessing  the  essential  features 
of  true  toxins  is  by  no  means  limited  to  the  bacterial  cell.  In 
the  plant  kingdom  such  substances  are  formed,  and  called  phyto- 
toxins.  Of  these,  the  best  known  are  ricin,  abriu,  crotin,  and 
robin.  Among  the  toxins  of  animal  origin,  zootoxins,  are  the 
venoms  of  poisonous  snakes,  lizards,  spiders  and  scorpions,  and 
the  serum  of  eels  and  snakes.  These  may  be  briefly  considered 
as  follows  : 

PHYTOTOXINS 

The  chief  phytotoxins  l  are  as  follows  : 

Ricin,  from  the  castor-oil  bean  (Ricinus  communis). 

Abrin,  from  the  seeds  of  Abrus  precatorius. 

Crotin,  from  the  seeds  of  Croton  tiglium. 

Robin,  from  the  leaves  and  bark  of  the  locust,  Robinia  pseu- 

doacacia. 

In  their  general  properties  all  these  substances  are  very  similar 
and  may  be  considered  together.  They  resemble  proteids  in 
many  respects,  for  they  can  be  salted  out  of  solutions  in  definite 
fractions  of  the  precipitate,  are  precipitated  by  alcohol,  and  are 
slowly  destroyed  by  proteolytic  enzymes.  For  some  time  they 
were  referred  to  in  the  literature  as  toxalbumins,  until  Jacoby 
stated  that,  by  combining  the  salting-out  method  with  trypsin 
digestion,  he  was  able  to  secure  preparations  of  ricin  and  abrin 
that  did  not  give  the  proteid  reactions.  This  seemed  to  place 
them  in  the  same  category  with  bacterial  toxins  and  enzymes, 
i.  6.,  large  molecular  colloids,  closely  resembling  the  proteid.s 
with  which  they  are  associated,  but  still  not  giving  the  usual 
proteid  reactions.  Because  of  their  great  similarity  to  bacterial 
toxins  this  seemed  a  very  probable  description,  and  it  has  been 
generally  accepted.  More  recent  work  by  Osborue,  Mendel, 
and  Harris2  however,  does  not  support  Jacoby' s  contention. 
They  found  the  toxic  properties  of  ricin  associated  inseparably 

1  Ke*sume"  of  literature  by  Jacoby,  Biochem.  Centralblatt,  1903  (1),  289. 

2  Amer.  Jour,  of  Physiol.,  1905  (14),  259. 

166 


PHYTOTOXINS  167 

with  the  coagulable  albumin  of  the  castor  beans,  and  were  able 
to  isolate  it  in  such  purity  that  one  one-thousandth  of  a  milli- 
gram (0.000001  gram)  was  fatal  per  kilo  of  rabbit,  and  solutions 
of  0.001  per  cent,  would  agglutinate  red  corpuscles.  The  toxic- 
ity was  also  impaired  or  destroyed  by  tryptic  digestion.  They 
consider  that  probably,  because  of  its  extremely  great  toxicity, 
Jacoby  was  able  to  get  active  preparations  that  contained  too 
little  active  substance  to  give  the  proteid  reactions.  As  they 
remark  :  "  If  one-thousandth  of  a  milligram  of  a  compound 
giving  on  analysis  every  indication  of  being  a  relatively  pure 
protein,  is  physiologically  active  in  the  degree  characterized  by 
our  experiments,  the  toxicity  of  any  impurity  must  be  infinitely 
greater  than  that  of  any  known  toxins."  In  this  connection 
may  be  mentioned  the  ultra-microscopic  studies  of  tetanus  anti- 
toxin quoted  by  v.  Behring L  which  showed  that  by  dialysis  a 
solution  containing  active  antitoxin  could  be  obtained  giving 
none  of  the  reactions  for  proteids,  yet  by  ultra-microscopic 
methods  it  could  be  demonstrated  that  proteids  were  present. 
Against  the  claim  that  the  toxic  principle  is  simply  carried  down 
with  the  proteid  is  the  fact  that  it  does  not  come  down  in  the 
first  fraction  that  is  precipitated,  the  globulin,  which  usually 
carries  down  all  impurities.  All  the  ricin  comes  down  between 
the  limits  of  one-fifth  and  one-third  saturation  with  ammonium 
sulphate,  exactly  as  does  the  albumin. 

Immunity. — The  phytotoxins  have  been  very  servicable  in 
the  study  of  immunity,  since  they  obey  the  same  laws  as 
bacterial  toxins  and  can  be  handled  in  more  definite  quantities. 
By  their  use  Ehrlich  first  determined  that  toxin  and  antitoxin 
act  quantitatively.  They  seem  to  possess  haptophore  and  tox- 
ophore  groups,  and  immunity  is  readily  obtained  against  them, 
not  only  by  subcutaneous  injection,  but  by  dropping  into  the 
conjunct! val  sac,  and  also  by  feeding,  showing  their  direct  absorb- 
ability and  their  resistance  to  digestion.  The  antitoxin  is  present 
in  the  milk  of  the  immunized  mother  and  immunizes  the  suckling ; 
but  little  is  carried  through  the  placenta  into  the  fetal  blood. 
The  immunity  is  specific,  ricin  antitoxin,  for  example,  not  pro- 
tecting against  abrin  (although  it  is  said  to  protect  against 
robin).  Roemer  found  that  in  animals  immunized  by  conjunctival 
application  the  eye  so  used  became  immune  to  the  local  action 
of  the  poison  before  the  other  eye  did,  indicating  a  local  develop- 
ment of  immune  substance.  In  general  immunization  the 
immune  substance  appears  first  in  the  spleen  and  bone-marrow. 
Normal  serum  gives  a  precipitate  with  ricin,  but  immune  serum 
1  Beitr.  exp.  Therapie,  1905,  H.  10,  p.  22. 


168  PHYTOTOXINS  AND  ZOOTOXINS 

gives  a  much  heavier  one.  Antiricin,  like  other  antitoxins,  is 
inseparable  from  the  proteids  of  the  serum. 

Physiological  Action. — Their  poisonous  action  is  mani- 
fold, most  prominent  being  agglutination  of  the  erythrocytes,  local 
cellular  destruction,  and,  to  a  less  extent,  hemolysis.  Jacoby 
believes  that  in  ricin  there  are  several  toxic  substances  differing 
in  physiological  properties,  similar  to  Ehrlich's  findings  in 
diphtheria  toxin  (toxones,  etc.).  By  long  action  of  pepsin-HCl 
upon  ricin,  he  secured  a  preparation  with  all  the  other  properties 
of  ricin  except  that  it  was  inactive  against  erythrocytes ;  the 
same  result  could  not  be  obtained  with  abrin.  Heating  to  65° 
or  70°  does  not  destroy  the  toxicity  of  phytotoxins,  but  boiling 
does.  There  is  a  latent  period  of  several  hours  after  injection 
of  the  poison,  the  onset  of  symptoms  being  sudden  ;  death  rarely 
occurs  in  less  than  fifteen  to  eighteen  hours  (Osborne  et  al). 

Flexner l  has  studied  particularly  the  histological  changes 
produced  by  ricin  and  abrin  poisoning  in  animals.  Both  act 
alike,  affecting  the  tissues  much  as  bacterial  toxins  do  (diph- 
theria). Fever,  albuminuria,  and  convulsions  are  followed  by 
exhaustion  and  lowered  temperature.  Punctiform  hemorrhages 
are  found  beneath  the  serous  surfaces,  with  fluid  in  the  peritoneal 
cavity.  At  least  in  the  case  of  ricin  the  hemorrhages  are  not 
due  to  blood  changes,  but  to  a  special  toxin  destroying  the 
endothelial  cells.2  There  occur  a  general  lymphatic  enlargement 
and  marked  changes  in  the  intestinal  mucosa,  with  swelling  of 
the  Peyer's  patches.  The  spleen  is  swollen  and  dark  in  color, 
as  also  is  the  liver,  which  shows  much  focal  necrosis.  Sub- 
cutaneous injection  causes  local  edematous  inflammation  without 
suppuration.  Histologically,  in  the  most  affected  organs  are 
found  much  cellular  necrosis  and  disintegration,  especially  of 
lymphoid  and  epithelial  cells.  Changes  in  the  capillary  endo- 
thelium,  fibrinous  thrombi,  and  abundant  hemorrhagic  extrav- 
asations are  wide-spread.  Probably  agglutinative  thrombosis 
by  red  corpuscles  plays  an  important  part  in  these  intoxications 
(Ehrlich).  The  great  amount  of  intestinal  injury  probably 
depends  upon  the  fact  that  these  poisons  are  largely  eliminated 
through  the  intestinal  mucosa. 

Mushroom  Poisons. — The  poisons  of  the  three  chief  poisonous 
mushrooms,  Amanita  muscaria,  Helvetia  esculentia,  and  Amanita  phal- 
loides,  differ  from  one  another  quite  essentially.  The  poisonous  prin- 
ciples of  the  first  and  second,  muscarin  and  helvellic  acid,  are  non-pro teid 
substances,  of  known  chemical  composition,  which  are  discussed  else- 

1  Jour.  Exper.  Med.,  1897  (2),  197. 

s  Amer.  Jour.  Med.  Sci.,  1903  (126),  206. 


THE  TOXIN  CAUSING  HAY  FEVER  169 

where  ;  but  the  Amanitaphalloides,  the  most  important  of  the  three,  owes 
its  toxic  properties  to  substances  which,  according  to  the  investigations 
of  Ford,1  are  true  phytotoxins.  At  least  two  poisonous  constituents  are 
present  in  A.  phalloides.  One,  the  phallln  of  Kobert,  is  powerfully 
hemolytic,  is  destroyed  by  heating  thirty  minutes  at  65°,  and  acts  directly 
upon  red  corpuscles  without  the  presence  of  serum,  thus  resembling  the 
bacterial  hemolysins.  Phallin  is  also  destroyed  by  the  action  of  pepsin 
and  pancreatin.  This  agent  produces  the  subcutaneous  edema,  hemo- 
globinuria,  and  pigmentation  of  the  spleen  observed  in  animals  into 
which  it  has  been  injected. 

The  hemorrhages,  necrosis,  and  fatty  degeneration  observed  in  poisoned 
animals  are  due  to  another  distinct  poison,  which  Ford  calls  amanito- 
toxin.  This  poison  is  thermostable,  not  being  destroyed  by  the  tem- 
perature that  destroys  the  activity  of  phallin  (65°),  but  it  does  not  resist 
heating  to  90°  or  over.  It  also  differs  from  phallin  in  being  resistant  to 
pepsin  and  pancreatin.  Animals  can  be  immunized  against  amanita 
extracts,  and  their  serum  will  neutralize  the  poisons.  Both  poisons 
resemble  the  bacterial  toxins  in  possessing  toxophore  and  haptophore 
groups,  which  are  quite  distinct  in  each  poison,  since  immunization  with 
the  thermostable  body  gives  a  serum  that  has  no  neutralizing  effect  upon 
phallin. 

THE    TOXIN   CAUSING   HAY-FEVER 

In  1902  Dunbar2  demonstrated  conclusively  that  typical  hay-fever,  in 
its  several  various  forms,  is  due  to  pollen  of  various  sources,  in  all, 
twenty-five  varieties  of  grass  and  seven  varieties  of  plants  of  other  sorts 
being  found  whose  pollen,  when  placed  upon  the  nasal  or  conjunctiva! 
mucous  membranes  of  hay-fever  patients,  cause  a  typical  attack  of  the 
disease.  In  Germany  the  disease  seems  to  come  chiefly  from  pollen  of 
the  grasses  and  grains  (rye  pollen  being  most  active),  whereas  in  America 
the  most  important  pollen  seems  to  come  from  members  of  the  Ambrosia 
(rag-weed)  and  Solidago  (goldenrod).  Dunbar  also  found  that  the 
toxic  constituent  could  be  dissolved  from  the  pollen  in  salt  solution,  and 
seemed  to  be  a  proteid:  The  proteid  constituents  of  the  pollen  of  rye 
have  been  studied  further  by  Kammann,3  who  found  three  proteids,  one 
of  which,  an  albumin,  was  found  to  contain  all  the  toxic  matter.  This 
constitutes  about  5.5  per  cent,  of  the  entire  weight  of  the  pollen,  is 
weakened  but  little  by  heating  to  80°,  and  is  not  destroyed  by  boiling  ; 
it  is  but  partly  destroyed  by  pepsin  and  trypsin,  and  resists  acids  but  not 
alkalies.  So  toxic  is  the  material  that  a  solution  containing  T^TT  milli- 
gram of  pollen  proteid,  which  amount  is  contained  in  two  or  three  pollen 
grains,  produces  a  reaction  in  susceptible  individuals,  but  large  amounts 
have  no  effect  on  normal  persons.  Dunbar  has  manufactured  an  anti- 
toxic serum  *  by  immunizing  horses  against  the  pollen,  which  seems  to 

1  Jour.  Infectious  Diseases,  1906  (3),  191 ;  Jour.  Exp.  Med.,  1906  (8),  437. 

2  Full  review  of  subject  and  literature  given  by  Glegg,  Jour,  of  Hygiene, 
1904  (4),  369;  concerning  etiology  see  Liefmann,  Zeit.  f.  Hygiene,  1904  (47), 
153;  also  Wolff-Eisner,  Deut.  med.  Woch.,  1906  (32),  138,  and  "Das  Heu- 
fieber,"  Munchen,  J.  F.  Lehmann,  1906. 

Hofmeister's  Beitr.,  1904  (5),  346. 

4  Wolff-Eisner  does  not  consider  the  toxic  substance  a  true  toxin,  but  Kam- 
mann (Berl.  klin.  Woch.,  1906,  p.  873)  upholds  Dunbar's  view  that  it  is  a  true 
toxin,  and  that  the  anti-serum  contains  a  true  antitoxin. 


170  PHYTOTOXINS  AND  ZOOTOXINS 

produce  decided  therapeutic  effects,  although  by  no  means  all  observers 
are  agreed  as  to  its  efficacy. l 

(The  effects  of  the  phytotoxins  on  the  blood  are  discussed 
under  "  Hemolysis  "  in  the  following  chapter.  Vegetable  hem- 
olytic  poisons  that  do  not  resemble  the  toxins,  e.  g.,  glueosides, 
etc.,  will  also  be  found  discussed  under  the  same  heading.) 

ZOOTOXINS2 

SNAKE    VENOMS 

This  important  class  of  poisons,  first  thoroughly  investigated 
by  Weir  Mitchell  (1860),  and  Mitchell  and  Reichert  (1883), 
has  recently  aroused  great  interest  through  its  relations  to  bac- 
terial toxins  and  the  problems  of  immunity.  The  poisons  of 
different  species  of  snakes  seem  to  have  much  in  common  with 
one  another,  whether  derived  from  the  Elaperine  snakes  (cobras 
and  numerous  other  Indian  and  Australian  snakes),  or  Viperidce 
(including  most  poisonous  American  snakes),  or  Hydrophince 
(the  poisonous  sea-snakes),  although  very  characteristic  differ- 
ences exist  between  each. 

The  essential  anatomical  differences  between  the  different  classes  of 
snakes  are  as  follows :  Colubridce,  which  include  all  the  non-poisonous 
snakes,  have  no  mechanism  for  injecting  poisons  into  their  victims. 
Colubridce  venenosce  are  venomous  snakes  resembling  in  many  particulars 
the  harmless  Colubrines,  but  having  short  poison  fangs,  firmly  fastened 
to  the  maxilla  in  an  erect  position  ;  in  this  class  are  included  the  cobra 
and  the  venomous  snakes  of  Australia.  Viperidce,  or  vipers,  are  char- 
acterized by  a  highly  specialized  apparatus  for  injecting  the  poison  ;  their 
poison  fangs  are  very  long,  and  the  maxillary  bone,  to  which  they  are 
fastened,  is  so  articulated  that  it  rotates  about  a  quarter  of  a  circle  when 
the  snake  strikes,  bringing  the  fangs  into  an  erect  position.  The  fangs 
are  canalized  and  pointed  at  the  end  like  a  hypodermic  needle,  and  the 
poison  is  forced  through  them  under  considerable  pressure  by  a  large 
muscle  that  contracts  over  the  salivary  gland.  Accessory  fangs  in  vari- 
ous stages  of  development  are  also  present  to  replace  any  fang  lost  in 
action.  All  the  poisonous  snakes  of  North  America,  with  one  insig- 
nificant exception,  belong  to  the  vipers,  and  to  a  special  class  known  as 
the  "pit  vipers,"  because  of  the  presence  of  a  deep  pit  of  unknown 
function  above  the  maxilla.  The  exception  mentioned  is  the  "coral 
snake ' '  found  on  the  coast  of  Florida,  around  the  Gulf  of  Mexico  and 
in  the  southeastern  states  ;  it  is  a  member  of  the  colubrine  poisonous 
snakes,  of  small  size,  and  seldom  causes  serious  poisoning.  The  poison- 
ous vipers  are  the  rattlesnakes  (Crotalus),  of  which  there  are  some  ten 
to  twelve  or  more  species,  and  Sistrurus,  of  which  there  are  two  species  ; 

1  See  Ingals,  Jour.  Amer.  Med.  Assoc.,  1906  (47),  376. 

2  Full  review  and  literature  given  by  Faust,  "  Die  tierischen  Gifte,"  Braun- 
schweig, 1906.     Hemolytic  Properties  of  Animal  Poisons,  discussed  by  Sachs, 
Biochemisches  Centralblatt,  1906  (5),  257. 


SNAKE  VENOMS  171 

the  copperheaded  adder  (Ancistrodon  contortrix)  and  the  water  moccasin 
(Ancistrodon  piscivorous). 

(The  classification  used  above  is  the  one  followed  in  most  publications 
on  poisonous  snakes  ;  a  more  modern  classification  divides  the  snakes 
(Ophidia)  into  several  series,  one  of  these  including  all  poisonous  snakes 
under  the  title  of  Proteroglypha,  and  dividing  this  series  into  the  three 
families  :  (1)  ElapiTice,  including  cobras,  coral  snakes,  etc. ;  (2)  Hydro- 
phince,  the  poisonous  sea-snakes  ;  (3)  Viperidce,  including  all  snakes  with 
erectile  fangs.1) 

The  source  of  the  venom  is  probably  in  part  the  blood,  since 
snake  blood  has  been  found  to  contain  poisons  very  similar  to 
some  of  those  in  the  venom  ;  therefore  these  are  presumably 
simply  filtered  out  by  the  venom  glands,  and  not  manufactured 
by  them.  Other  poisonous  constituents  of  venom  are  not  found 
in  snake  serum,  and  therefore  are  probably  manufactured  by  the 
venom  gland.  Apparently  many  of  the  harmless  snakes  pro- 
duce a  poisonous  saliva,  since  extracts  of  their  glands  are  said 
by  Blanchard 2  to  possess  the  properties  of  the  venoms,  and  if 
so  these  snakes  are  harmless  chiefly  because  they  lack  an  appa- 
ratus for  injecting  the  poison.  As  a  rule,  however,  the  venom 
glands  are  much  more  highly  developed  in  the  poisonous  snakes, 
and  are  connected  with  a  specialized  injection  apparatus ;  in 
structure  they  are  compound  racemose  glands. 

Properties  of  Venom. — As  ejected,  the  venom  is  weakly 
acid  or  neutral  in  reaction,  and  free  from  bacteria,  contrary  to 
earlier  ideas  (Langmann).  Its  specific  gravity  is  1030  to  1077, 
and  it  contains  a  large  amount  of  solids,  generally  20  to  30  per 
cent,  by  weight.  These  are  precipitated  by  alcohol,  ether,  tan- 
nin, and  iodin,  but  do  not  adhere  to  precipitates  of  phosphates 
as  do  enzymes  and  toxins  (Calmette).  They  do  not  diffuse 
through  dialyzing  membranes.  When  dried,  the  venom  can  be 
kept  almost  indefinitely  without  losing  its  strength,  specimens 
over  twenty  years  old  having  been  found  unimpaired.  Glycerin 
and  alcohol  also  seem  not  to  injure  it,  but  oxidizing  agents  of 
all  kinds  are  very  destructive.  Light  impairs  the  power  of 
venoms,  as  also  does  radium  (Phisalix  3 ).  Eosin  and  erythrosin 
also  reduce  the  power  of  venom  through  their  photodynamic 

1  For  a  full  discussion  of  the  characteristics  of  the  poisonous  snakes  of 
North  America,  see  the  monograph  with  that  title  by  Stejneger,  Report  of  U. 
S.  National  Museum,  1893,  Washington.     A  good  summary  is  also  given  by 
Langmann,  Reference  Handbook  of  Medical  Sciences,  vol.  8,  p.  708.     Con- 
cerning poisonous  sea-snakes,  Hydrophidia,  see   Boulanger,  Natural  Science, 
1892  (1),  44.     The  poisonous  snakes  of  India  are  described  by  Fayrer,  in  "  The 
Thanatophidia  of  India,"  London,  1874. 

2  Compt.  Rend.  Soc.  Biol.,  1894  (46),  35. 

3  Compt.  Rend.  Soc.  Biol.,  1904  (56),  327. 


172  PHYTOTOXINS  AND  ZOOTOXIXS 

action,  affecting  the  neurotoxic  properties  less  than  the  hemato- 
toxic  components  (Noguchi l ). 

Much  work  has  been  done  upon  the  nature  of  the  constituents 
of  venom.  As  early  as  1843  Prince  Lucien  Bonaparte  found 
that  there  were  proteids  in  the  venom,  which  was  corroborated 
by  Mitchell  in  1861.  In  1883  Mitchell  and  Reichert  described 
two  poisonous  proteid  constituents  of  venom,  one  of  which  was 
coagulable  by  heat  and  seemed  to  be  a  globulin ;  the  other 
resembled  the  proteoses  (they  called  it  "  peptone,"  according  to 
the  nomenclature  of  that  time).  To  the  globulin  they  ascribed 
the  local,  irritating  properties  of  venom  ;  to  the  albumose,  the 
systemic  intoxication.  Corresponding  to  their  action,  venoms 
of  different  serpents  were  found  to  vary  greatly  in  the  propor- 
tions of  these  proteids.  Cobra  venom,  which  acts  chiefly  sys- 
temically,  contains  98  per  cent,  of  albumose  and  but  2  per  cent, 
of  globulin  ;  rattlesnake  venom,  with  its  marked  local  effects, 
contains  25  per  cent,  of  the  irritating  globulin ;  moccasin 
venom  contains  8  per  cent,  of  globulin.  Several  other  observers 
soon  corroborated  the  main  facts  of  Mitchell  and  Reichert's 
report ;  but,  as  has  been  seen  in  connection  with  the  consideration 
of  the  composition  of  enzymes,  toxins,  etc.,  the  fact  that  a  sub- 
stance is  carried  down  with  a  proteid  is  no  proof  that  it  is  itself  a 
proteid.2  What  has  been  established  is  merely  that  the  irritat- 
ing component  of  venom  can  be  destroyed  by  heat,  and  is 
removed  with  the  globulin  in  fractional  separation ;  while  there 
remains  a  substance  not  destroyed  by  boiling,  which  comes  down 
at  least  in  part  with  the  albumoses  of  the  venom,  and  causes 
chiefly  systemic  manifestations. 

Enzymes  in  Venoms. — As  venom  causes  rapid  liquefaction 
of  tissues  into  which  it  is  injected,  Flexner  and  Noguchi 3  tested 
crotalus  and  cobra  venom  for  proteases,  and  found  that  they 
digested  muscle  rapidly,  and  also  gelatin  and  unboiled  fibrin  ; 
whereas  boiled  fibrin  and  boiled  egg-albumen  were  undigested. 
Wehrmann 4  found  that  venom  (cobra  ?)  digests  fibrin  and  inverts 
saccharose,  but  does  not  digest  starch.  Martin 5  found  fibrin 
ferments  in  various  venoms. 

Toxicity. — Calmette  has  determined  the  toxicity  of  several 
venoms,  and  gives  the  following  figures  : 

1  Jour.  Exper.  Med.,  1906  (8),  252. 

2  Faust  ("  Tierische  Gifte,"  p.  60)  has  described  a  non-proteid,  nitrogen-free 
poison  in  cobra  venom  which  he  calls  "ophiotoxin."     It  has  a  curare-like 
action  and  also  paralyzes  the  central  nervous  system.     Its  general  properties 
resemble  those  of  picrotoxin  and  sapotoxin. 

3  Univ.  of  Penn.  Med.  Bull.,  1902  (15),  360. 

4  Ann.  d.  T  Inst.  Pasteur,  1898  (12),  510. 

5  Jour,  of  Physiol.,  1905  (32),  207. 


SNAKE  VENOMS  173 

1  gm.  cobra  or  aspis  kills 4000  kgm.  of  rabbit. 

1  gm.  hoplocephalus  kills 3450      "      "       " 

1  gm.  fer  de  lance  or  pseudechis  kills  ....    800     "      "       " 

1  gm.  Crotalus  horridus  kills 600     "     "   '     " 

1  gm.  Pelias  berus  kills 250     "      "        " 

The  danger  of  the  bite  depends  not  only  upon  the  difference 
in  the  strength  of  the  venom  of  different  varieties  of  serpents,  but 
also  upon  the  size  of  the  snake,  the  time  of  year  and  condition  of 
hunger  or  plenty,  and  particularly  whether  the  entire  discharge 
is  injected  successfully  or  not.  Probably  in  the  majority  of 
strikes,  by  no  means  all  the  fluid  ejected  by  both  fangs  is  injected 
beneath  the  skin  of  the  victim.  A  large  diamond  rattler  may 
eject  as  much  as  a  teaspoonful  of  venom  at  one  discharge  and 
such  a  dose  would  usually  be  fatal.  Repeated  ejections  decrease 
the  strength  of  the  venom  rapidly,  until  it  may  have  almost  no 
toxicity.  In  general,  venom  is  most  active  in  warm  weather 
and  immediately  after  the  snake  has  fed ;  in  winter  its  toxicity 
is  slight. 

The  mortality  in  America  from  snake-bites  is  very  hard  to 
ascertain,  various  authors  giving  figures  at  wide  variance.  Weir 
Mitchell  gives  one  series  with  a  mortality  of  25  per  cent.,  and 
another  series  in  which  it  was  12  per  cent.  ;  Ellzey  gives  15  per 
cent.  These  figures  are  probably  high,  since  fatal  cases  are 
much  more  likely  to  find  their  way  into  the  literature  than 
those  in  which  the  results  are  trifling.  Some  authors  go  so  far 
as  to  say  that  there  are  no  authentic  cases  of  death  from  copper- 
heads or  moccasins,  but  this  is  undoubtedly  incorrect.1  How- 
ever, the  reputed  danger  from  these  snakes  is  undoubtedly  much 
exaggerated,  many  deaths  from  snake-bites  of  all  kinds  being 
due  to  the  treatment  rather  than  to  the  bite.  The  poisonous 
snakes  of  Australia,  although  numerous,  are  not  very  virulent, 
and  the  mortality  is  given  as  about  7  per  cent.  A  full  charge 
of  venom  from  the  cobra  and  many  other  Indian  snakes  is  in- 
evitably fatal  (Fayrer).  The  crotaline  snakes  of  the  tropics  are 
more  venomous  than  those  of  the  north,  Lacheris  lanceolatus  of 
Central  America  and  Mexico  being  nearly  as  dangerous  as  the 
cobra. 

When  venom  is  taken  into  the  stomach  in  the  intervals  of 
digestion,  enough  may  be  absorbed  to  produce  death,  especially 
in  the  case  of  those  venoms  which  contain  a  large  proportion  of 
the  albumose,  which  is  dialyzable ;  but  during  active  digestion 
the  venom  undergoes  alteration  and  is  rendered  harmless.  It 
has  been  found  experimentally  in  animals  that  cobra  venom 

1  Concerning  copperhead  poisoning  see  Yarrow,  Amer.  Jour.  Med.  Sci., 

1884  (87),  422. 


174  PHYTOTOXINS  AND  ZOOTOXINS 

placed  in  the  stomach  causes  ordinarily  no  harm  whatever,  but 
if  a  loop  of  the  intestine  is  isolated,  a  fistula  established  and 
allowed  to  heal,  venom  introduced  through  this  opening  always 
produces  death.  It  is  probably  not  the  pepsin  and  hydrochloric 
acid  that  destroys  the  venom,  but  the  trypsin.  If  the  bile-duct 
is  ligated,  the  venom  is  destroyed  just  the  same.  Much  of  the 
venom  seems  to  be  eliminated  into  the  stomach,  no  matter  how 
it  is  introduced  into  the  system,  and  apparently  it  is  also  partly 
excreted  by  the  kidneys.  Rattlesnake  venom  seems  not  to  be 
absorbed  through  mucous  membranes. 

Physiological  Action. — As  indicated  in  the  preceding 
paragraph,  the  eifects  of  the  bites  of  different  classes  of  snakes 
are  quite  different.  Langmann  describes  the  symptoms  as 
follows  : 

Cobra  Poisoning. — "  Within  an  hour,  on  an  average,  the  first  con- 
stitutional symptoms  appear :  a  pronounced  vertigo,  quickly  followed 
by  weakness  of  the  legs,  which  is  increased  to  paraplegia,  ptosis,  falling 
of  the  jaw  with  paralysis  of  the  tongue  and  epiglottis  ;  at  the  same  time 
there  exists  an  inability  to  speak  and  swallow,  with  fully  preserved  sen- 
sorium.  The  symptoms  thus  resemble  those  of  an  acute  bulbar  paralysis. 
The  pulse  is  of  moderate  strength  until  a  few  minutes  after  the  cessation 
of  respiration ;  the  latter  becomes  slower,  labored,  and  more  and  more 
superficial  until  it  dies  out  almost  imperceptibly.  Death  occurs  at  the 
latest  within  fifteen  hours  ;  in  32  per  cent,  of  all  cases  in  three  hours. 
There  are  very  few  local  changes." 

Viper  Poisoning. — "  After  the  bite  of  a  viper  the  local  changes  are 
most  pronounced  ;  there  are  violent  pains  in  the  bleeding  wound,  hem- 
orrhagic  discoloration  of  its  surroundings,  bloody  exudations  on  all  the 
mucous  membranes,  and  hemoglobinuria.  Usually  somewhat  later  than 
in  cobra  poisoning  constitutional  symptoms  develop  ;  viz.,  great  prostra- 
tion with  nausea  and  vomiting,  blood  pressure  falls  continuously,  and 
respiration  grows  slow  and  stertorous.  After  a  temporary  increase  in 
reflexes,  paresis  supervenes,  with  paraplegia  of  the  lower  extremities, 
extending  in  an  upward  direction  and  ending  in  a  complete  paralysis. 
It  therefore  resembles  an  acute  ascending  spinal  paralysis.  If  the 
patient  recovers  from  the  paralysis,  a  septic  fever  may  develop ;  not 
rarely  there  remain  suppurating  gangrenous  wounds,  which  heal 
poorly." 

It  will  be  noticed  that  there  is  lacking  the  usual  period  of 
incubation  that  follows  injection  of  bacterial  toxins,  and  if  it 
happens  that  the  venom  has  been  injected  directly  into  one  of 
the  veins,  death  may  occur  within  a  few  minutes.  When  re- 
covery occurs,  the  disappearance  of  symptoms  is  remarkably 
abrupt,  within  a  few  hours  a  desperately  sick  person  becoming 
almost  entirely  free  from  all  evidences  of  the  intoxication. 

Pathological  Anatomy. — Postmortem  examination  shows  changes 
varying  with  the  nature  of  the  poisonous  snake  that  has  caused  death. 


SNAKE  VENOMS  175 

In  the  case  of  a  cobra  bite,  according  to  Martin,  the  areolar  tissue  about 
the  wound  is  infiltrated  with  pinkish  fluid  ;  the  blood  is  often  fluid  ;  the 
veins  of  the  pia  are  congested,  and  the  ventricles  often  contain  turbid 
fluid  ;  the  kidneys  may  show  much  congestion.  When  death  occurs  in 
a  few  minutes,  enormous  general  intravascular  clotting  is  found,  which 
seems  to  be  the  cause  of  death.  After  death  from  a  viper  bite  the  site 
of  the  wound  is  the  seat  of  intense  edema  and  extravasation  of  blood  ;  if 
in  the  muscles,  these  are  much  softened  and  disorganized.  Hemorrhages 
are  found  in  all  organs  and  in  the  intestinal  tract.  If  death  occurs 
after  several  days  it  is  generally  because  of  sepsis,  and  shows  the  usual 
changes  of  this  condition  ;  in  addition,  as  a  rule,  to  marked  gangrenous, 
ulcerative,  and  sloughing  processes  at  the  site  of  the  bite. 

H isto logically  there  are  found,  in  addition  to  innumerable  hemor- 
rhages in  nearly  all  the  organs,  many  vessels  plugged  with  thrombi 
composed  of  more  or  less  hemolyzed,  agglutinated  erythrocytes.  The 
changes  produced  in  the  nervous  tissue  by  the  Australian  tiger  snake 
are  described  by  Kilvington,1  who  found  marked  chromatolysis,  the 
Nissl  bodies  breaking  into  dust-like  particles,  and  eventually  all  stain- 
able  substance  disappearing  from  the  cytoplasm  ;  the  nucleus  retains 
its  central  position,  but  often  loses  its  outline  and  may  disappear.  The 
cells  around  the  central  canal  of  the  cord  are  most  affected.  There  are 
no  inflammatory  changes  in  the  nervous  system,  and  if  death  occurs  very 
quickly  there  may  be  no  microscopic  alterations.  Hunter2  found  simi- 
lar changes  in  the  Nissl  bodies  in  both  krait  and  cobra  poisoning  ;  in  the 
medullated  fibers  he  found  the  myelin  sheath  converted  into  ordinary 
fat.  Nowak 3  studied  experimental  animals,  and  found  much  fatty 
change  in  the  livers,  even  if  death  occurred  one-half  hour  after  poison- 
ing ;  also  focal  necrosis  in  the  liver,  acute  parenchymatous  alterations  in 
the  kidney,  and  pneumonic  patches  in  the  lungs. 

Effects  on  the  Blood. — There  has  been  much  discussion  concerning 
the  part  played  by  the  abundant  and  prominent  intravascular  clotting  in 
causing  death  after  snake-bite.  Lamb 4  states  that  when  venoms  are 
slowly  absorbed  the  coagulability  of  the  blood  is  decreased  and  it  is  found 
fluid  after  death,  but  when  a  fatal  dose  of  venom  (viper)  is  rapidly 
absorbed,  clotting  is  increased  and  thrombosis  is  the  chief  cause  of  death. 
Martin  has  demonstrated  very  active  fibrin  ferments  in  snake  venom 
(loc.  cit. ).  It  is  highly  probable,  however,  that  many  of  the  thrombi 
of  venom  poisoning  are  not  produced  by  coagulation  of  fibrin,  but  by 
agglutination  of  the  red  corpuscles,  which  Flexner6  has  shown  can 
cause  large  clots  in  the  heart  and  great  vessels,  as  well  as  "hyalin" 
thrombi  in  the  small  vessels. 

Nature  of  Venoms. — The  varied  effects  produced  by 
venoms  have  been  found  to  be  due  to  a  number  of  poisonous 
elements  which  they  contain,  and  which  have  been  distinguished 
and  separated  from  one  another  by  Flexner  and  Noguchi.6 

1  Jour,  of  Physiol.,  1902  (28),  426. 

2  Glasgow  Med.  Jour.,  1903  (59),  98. 

3  Ann.  d.  1'  Inst.  Pasteur,  1898  (12),  369. 
*  Indian  Medical  Gazette,  Dec.,  1901. 

5  Univ.  of  Penn.  Med.  Bull.,  1902  (15),  324. 

6  Jour.  Exp.  Med.,  1903  (9),  257;  Univ.  of  Penn.  Med.  Bull.,  1902  (15), 
345. 


176  PHY  TO  TOXINS  AND  ZOO  TOXINS 

These  are  hemotoxins  (hemolysins  and  hemagglutinins),  leucocy- 
tolysinsy  neurotoxins,  and  endotheliotoxins  (hemorrhagin).  In 
another  place  (see  "Hemolysis")  the  nature  of  thehemolytic  agent 
is  discussed,  and  the  important  observation  of  Flexner  and 
Noguchi,  that  the  venom  hemolysin  is  in  the  nature  of  an 
amboceptor,1  is  described.  Venom  agglutinin  is  quite  inde- 
pendent of  the  hemolysin,  for  it  is  destroyed  by  heating  to  75°- 
80°,  whereas  the  hemolysin  is  destroyed  only  partly  at  100°. 
Agglutinin  acts  in  the  absence  of  serum  complement,  and  there- 
fore is  not  an  amboceptor  like  the  hemolysin ;  it  is  apparently 
more  like  the  toxins  in  its  nature.  The  agglutination  of  the 
corpuscles  does  not  interfere  with  their  subsequent  hemolysis. 

The  leucocytotoxins  are  quite  distinct  from  the  hemolysins, 
for  after  saturating  .  all  the  hemolytic  amboceptors  with  red 
corpuscles,  the  venom  still  shows  its  effects  on  the  leucocytes, 
which  effects  consist  in  cessation  of  motility  and  disintegration, 
affecting  particularly  the  granular  cells.  The  leucocytotoxin, 
however,  resembles  the  hemolysin  in  that  it  appears  to  be 
an  amboceptor.  Leucocytes  are  also  agglutinated  by  venom, 
possibly  by  the  same  agglutinin  that  acts  on  the  red  corpuscles. 

By  saturating  venom  with  either  red  corpuscles  or  nerve-cells 
it  is  possible  to  prove  that  the  toxic  principle  for  each  is  distinct 
and  separate.  Other  sorts  of  cells,  however,  are  able  to  com- 
bine, or  at  least  remove  some  parts  of  the  toxic  elements,  but 
to  a  much  less  degree.  The  neurotoxin,  like  the  hemolysin,  is 
an  amboceptor,  and  since  venom  contains  no  complement,  the 
neurotoxin  has  first  to  be  supplied  with  complement  by  the 
victim's  blood  before  it  can  harm  the  cells.  This  is  a  remark- 
able example  of  a  substance,  the  complement,  which  is  normally 
intended  for  defense,  acting  as  a  toxic  agent. 

The  pronounced  hemorrhage-producing  property  of  serums, 
particularly  that  of  the  rattlesnake,  was  also  found  to  be  due  to 
a  specific  toxin  acting  on  the  endothelium  of  the  capillaries  and 
small  veins,  and  not  to  the  changes  in  the  blood  itself,  as  had 
formerly  been  thought.  This  endotheliotoxin,  which  Flexner 
and  Noguchi  call  "  hemorrhagin/'  is  quite  distinct  from  the 
other  toxic  substances,  being  destroyed  at  75°,  a  temperature 
that  leaves  the  neurotoxin  and  hemolysin  uninjured. 

Variations  in  Venoms. — In  distribution  among  the  vari- 
ous poisonous  reptiles  these  toxins  are  also  quite  distinct  from 
one  another,  which  explains  the  difference  in  the  effects  of  bites 

1  This  use  of  the  term  hemolysin  is  usual,  but  not  strictly  correct,  for  the 
amboceptor  by  itself  is  not  hemolytic.  A  more  exact  statement  would  be  that 
the  venom  hemolysin  is  an  amboceptor-complement  complex  (Ricketts). 


SNAKE   VENOMS  177 

by  snakes  of  various  kinds.  Cobra  venom  contains  chiefly 
neurotoxin,  hence  the  symptoms  of  cobra  bite  are  largely  of 
nervous  origin,  with  but  little  local  tissue  change.  Rattlesnake 
venom  owes  its  effects  chiefly  to  hernorrhagin,  hence  the  marked 
local  necrosis  and  extravasations  of  the  blood,  and  the  general- 
ized hemorrhages  ;  the  nervous  effects  following  viper  bite  are 
probably,  in  part,  due  to  hemorrhages  in  the  nervous  tissue. 
Cobra  venom  produces  great  hemolysis  and  little  agglutination. 
Rattlesnake  venom  has  relatively  little  agglutinative  or  hemo- 
lytic  power.  Water  moccasin  and  copperhead  venoms  are  more 
agglutinative  than  either,  and  intermediate  in  hemolytic  strength ; 
they  cause  much  local  tissue  destruction. 

The  exact  action  of  cobra  venom  on  various  centers  and  organs  has 
been  studied  by  Elliot.1  It  raises  blood  pressure  when  in  dilution  of 
1  : 10, 000, 000,  by  contracting  vessels  and  stimulating  the  heart;  low  lethal 
doses  kill  by  paralyzing  the  respiratory  center. 

Krait  (Bungarus  ccerulues)  venom  acts  similarly,  but  less  powerfully, 
and  cannot  be  neutralized  by  Calmette's  antivenin.2 

Sea-snake  venoms  are  by  far  the  most  poisonous  of  all.  For  Enhy- 
drina  valakadien  the  lethal  dose  for  rabbits  is  0.00006  gram  per  kilo 
body  weight.  It  acts  by  vagus  stimulation  and  paralysis  of  respiratory 
centers  and  of  motor  nerve-endings.3 

Russell'  s  viper  (Daboia  Russellii]  owes  its  effects  chiefly  to  intravascu- 
lar  clotting,  according  to  Lamb  and  Hanna, 4  and  contains  no  neurotoxin. 
It  is  not  neutralized  by  Calmette's  antivenin.  The  clots  are  due  to 
agglutination  and  contain  no  fibrin  (Flexner).5 

The  "  Gil  a  monster "  (Heloderma  suspectum)  seldom  causes  serious 
poisoning  in  man,  but  may  kill  small  animals,  such  as  frogs.  Its  poison 
is  only  slightly  hemolytic;  but  produces  degenerative  changes  in  the 
nervous  system  (Langmann). 

I/oss  of  Bactericidal  Powers. — The  frequency  of 
marked  and  persistent  sloughing  and  suppuration  at  the  site  of 
snake-bites,  particularly  from  the  vipers,  and  the  common  termi- 
nation in  sepsis,  was  attributed  by  Welch  and  Ewing6  to  a 
loss  of  bactericidal  power  of  the  blood,  which  they  found  followed 
experimental  venom  poisoning.  This  has  been  nicely  explained 
by  Flexner  and  Noguchi  as  the  result  of  saturation  of  serum 
complement  by  the  numerous  amboceptors  of  the  venoms,  so 
that  no  complement  is  left  for  the  serum  to  use  against  the  bac- 
teria. In  serum  whose  complements  do  not  combine  with  the 

1  Lancet,  1904  (i),  715. 

2  Elliot,  Sillar,  and  Carmichael,  Lancet,  1904  (ii),  142. 

'Eraser  and  Elliot,  Lancet,  1904  (ii),  141 ;  also  Kogers,  Jour,  of  Physiol., 
1903  (30),  iv.  The  above  are  also  given  completely  in  the  Philosophical 
Transactions  of  the  Koyal  Society,  1904-5,  vol.  187. 

4  Jour,  of  Path,  and" Back,  1902  (8),  1. 

6  Thorough  study  by  Van  Denburgh  and  Wright,  Amer.  Jour,  of  Physiol., 
1900  (4),  209. 

6  Lancet,  1894  (1),  1236;  Ewing,  Med.  Record,  1894  (45),  663. 

18 


178  PHYTOTOXINS  AND  ZOOTOXINS 

venom  amboceptors  (e.  g.,  Nedurus)  the  normal  bactericidal 
powers  are  not  in  the  least  impaired  by  the  addition  of  venom. 

Snake  Serum. — The  serum  of  serpents  is  also  toxic  for 
other  animals,  even  when  the  serpent  is  not  a  venomous  one  ; 
e.  g.j  the  harmless  pine  snake  (Pityophis  cateniferis).  The  toxic- 
ity  of  snake  serum  seems  to  depend  chiefly  upon  its  hemotoxic 
effects  (hemagglutination  and  hemolysis),  the  toxic  substances 
being  in  the  nature  of  amboceptors  and  similar  to,  but  not  alto- 
gether identical  with,  the  amboceptor  of  the  venoms.  Crotalus 
tissues  also  produce  poisoning  in  proportion  to  the  blood  they 
contain,  but  are  without  toxic  effects  of  their  own  (Flexner 
and  Noguchi). 

Antivenin. — Snake  venom  has  the  essential  property  of  all 
true  toxins  of  immunizing,  with  the  appearance  of  an  antitoxin 
in  the  blood.  The  first  successful  immunizations  seem  to  have 
been  made  by  Sewall,1  but  the  practical  production  of  antitoxic 
serum  was  first  accomplished  by  Calmette 2  and  by  Eraser.3 
This  antivenin  neutralizes  the  neurotoxins  and  hemolysins  of 
venoms  of  any  origin,  and  also  of  snake  serums,  and,  therefore, 
is  quite  effective  against  cobra  and  similar  venoms  which  pro- 
duce chiefly  neurotoxic  and  hemolytic  changes.  This  indicates 
that  these  toxic  substances  are  of  identical  nature  in  all  snakes, 
no  matter  how  dissimilar  the  snakes  may  be.  Cobra  antivenin 
does  not,  however,  neutralize  the  hemorrhagin  of  rattlesnake 
venom,  for  the  venoms  used  by  Calmette  do  not  contain  this 
principle  abundantly.  A  special  antitoxin  against  rattlesnake 
venom  and  its  hemorrhagic  toxin  has  been  successfully  prepared 
by  Noguchi.4  This  crotalus  antivenin  also  neutralizes  hemo- 
lysins of  all  sorts  of  venoms,  and  also  of  snake  serums. 

Presumably  antivenin  neutralizes  venoms  in  exactly  the  same 
way  that  antitoxin  neutralizes  toxins ;  i.  e.,  cell  receptors  are 
thrown  off  from  the  injured  cells  during  immunization,  which 
combine  with  venom  amboceptors  in  the  blood,  and  thus  prevent 
their  combining  with  the  cells.  Antivenin  also  prevents  the 
inhibiting  action  of  venom  on  bactericidal  serum,  indicating  that 
it  prevents  the  venom  amboceptors  from  binding  the  serum 
complement.  The  reaction  of  venom  and  antivenin  is  certainly  a 
chemical  one,  being  likened  by  Kyes 5  to  that  of  strong  acids 
upon  strong  bases. 

1  Jour,  of  Physiol.,  1887  (8),  203. 

2  Ann.  d.  F  Inst.  Pasteur.  1894  (6),  275 ;  also  subsequent  articles  in  1897 
(11),  214;  1898  (12),  343.     ' 

3  British  Med.  Jour.,  1895  (i),  1309. 

4  Univ.  of  Penn.  Med.  Bull.,  1904  (17),  154. 
5Berl.  klin.  Woch.,  1904  (41),  494. 


SCORPION  POISON  179 

Lamb l  found  that  antivenin  for  cobra  acts  as  a  precipitin  for 
cobra  venom,  but  considered  it  not  specific  for  cobra  venom, 
as  it  causes  precipitation  to  varying  degrees  in  other  venoms. 
Hunter,2  however,  states  that  the  precipitin  is  specific.  It  does 
not  cause  precipitation  with  cobra  serum,  but  precipitins  for  cobra 
serum  do  precipitate  cobra  venom  (Hunter).  The  precipitin  for- 
mation is  not  essentially  related  to  antitoxin  formation.  Flexner 
and  Noguchi  also  observed  that  crotalus  antivenin  is  strongly 
precipitating  for  crotalus  serum,  less  so  for  crotalus  venom,  and 
but  slightly  for  pine-snake  serum  ;  Calmette's  antivenin  is  with- 
out precipitating  action  on  either  crotalus  venom  or  serum. 

As  is  well  known,  snakes  are  nearly  or  quite  insusceptible  to 
snake  venom.  Cunningham3  found  that  serum  of  cobras  was 
devoid  of  antitoxic  property,  so  the  immunity  of  snakes  must 
be  ascribed  to  an  absence  of  cell  receptors  in  their  tissues,  with 
which  their  venom  amboceptor  can  combine.  The  reputed 
immunity  of  the  mongoose  and  hedgehog  depends  partly  on  a 
relatively  low  susceptibility,  but  probably  more  on  the  agility 
of  the  mongoose  and  the  defensive  spines  of  the  hedgehog. 

SCORPION  POISON4 

This  poison  is  secreted  by  a  pair  of  specialized  glands  in  the 
posterior  segment  of  the  elongated  abdomen,  surrounded  by  a 
firm  capsule  with  a  sharp  apex  through  which  the  poison  is 
discharged.  Its  effect  on  man  is  usually  confined  to  local  pain, 
swelling,  and  occasionally  phlegmonous  inflammation  with  con- 
stitutional symptoms  after  bites  from  the  largest  species.  In 
Africa  a  large  scorpion  (Androctonus)  exists,  that  is  reputed 
frequently  to  cause  fatal  poisoning,  especially  in  children.  The 
majority  of  serious  results  following  scorpion  bites,  as  well  as 
bites  of  poisonous  insects  to  be  considered  later,  are,  however, 
due  to  infection  of  the  wound,  which  occurs  readily  because  of 
local  necrosis  and  hemorrhages,  and  also  because  of  the  unfavor- 
able conditions  existing  in  tropical  climates.  Apparently  these 
bites  favor  local  infection  much  as  do  those  of  vipers. 

When  general  symptoms  do  occur,  they  are  described  as" 
resembling  strychnine  poisoning,  with  trismus,  stiffness  of  the 
neck  and  eventually  of  the  respiratory  muscles,  which  seems  to 

1  Lancet,  1902  (ii),  431  ;  1904  (i),  916. 

2  Jour,  of  Physiol.,  1905  (33),  239. 

3  Nature,  1896  (55),  139. 

4  A  complete  discussion  of  the  literature  on  poisonous  invertebrates,  etc., 
is  given  by  v.  Fiirth,  "  Vergleichende  chemische  Physiologic   der  niederen 
Tiere,"  Jena,  1903  ;  and  by  Faust,  "  Die  tierischen  Gifte,"  Braunschweig,  1906. 


180  PHYTOTOXINS  AND  ZOO  TOXINS 

be  the  chief  cause  of  death  (Cavorez).  Thompson,1  however, 
observed  only  seldom  severe  symptoms,  consisting  of  general 
paralysis  that  passed  off  in  a  few  hours.  Most  experimenters 
with  scorpion  poison  describe  it  as  chiefly  a  nerve-tissue  poison, 
but  it  also  seems  to  act  as  a  hemolysin  and  agglutinin  (Bellesme 
and  Sanarelli).  Calmette 2  gives  the  lethal  dose  for  a  guinea-pig 
as  0.5  milligram,  while  Phisalix  and  Varigny  put  it  at  0.1 
milligram  and  state  that  scorpion  blood  is  also  poisonous. 
Wilson3  found  its  toxicity  equal  to  0.1  gram  per  million,  that 
is,  one  gram  of  poison  will  kill  10,000,000  grams  of  guinea- 
pig,  hence  it  is  much  stronger  than  cobra  venom.  The  average 
amount  of  toxin  in  an  Egyptian  scorpion  (Buthus  quinque- 
striatus]  is  sufficient  to  kill  about  35  kilos,  which  agrees  with 
the  fact  that  fatal  poisoning  by  this  scorpion  is  rare  in  adults, 
but  reaches  60  per  cent,  in  children.  The  venom  is  harmless 
when  taken  into  the  stomach,  and  is  said  to  be  made  inactive 
by  ammonia,  calcium  hypochlorite,  and  peroxide  of  hydrogen. 
Calmette  claims  that  antivenin  for  cobra  in  part  neutralizes 
scorpion  poison.  A  large  number  of  naturalists  and  raconteurs 
have  furnished  interesting  tales  of  suicide  by  scorpions,  which 
are  more  than  improbable  in  the  light  of  our  present  knowledge 
concerning  natural  immunity. 

SPIDER  POISON 

The  poison  apparatus  of  the  spiders  consists  of  two  long 
pouches  lying  in  the  thorax  and  extending  into  the  jaws,  at  the 
apex  of  which  the  poison  is  discharged.  Some  of  the  larger 
members  of  the  family  are  very  poisonous,  e.  g.y  the  Malmi- 
gnatte  (Lathrodectes  tredecimguttatas),  of  the  vicinity  of  the  lower 
Volga  in  southern  Russia,  is  said  to  have  destroyed  70,000 
cattle  in  one  tyear,  the  bite  being  fatal  in  12  per  cent,  of  all 
cases,  although  rarely  killing  man.  Other  members  of  this 
species  in  Chili,  Madagascar,  and  other  countries  are  not  much 
less  venomous.  Robert  has  studied  the  poison  of  Malmignatte 
and  found  it  distributed  throughout  the  body  of  the  spider, 
•even  in  the  eggs,  and  resembling  in  nature  the  snake  venoms. 
It  is  destroyed  by  heating,  and  seems  to  be  of  proteid  nature ; 
the  chief  effect  is  upon  the  nervous  system  and  heart. 

A  number  of  common  spiders  investigated  by  Kobert 4  were 

1  Proc.  Acad.  Nat.  Sci.  of  Philadelphia,  1886,  p.  299. 

2  Ann.  Inst.  Pasteur,  1895  (9),  232. 

3  Kecords  of  Egyptian   Gov't.,   School   of   Med.,   1904 ;  abst.  in  Jour,  of 
Physiol.,  1904  (31),  p.  xlviii. 

"  Beitriige  zur  Kentnisse  der  Giftspinnen,"  Stuttgart,  1901. 


SPIDER  AND  CENTIPEDE  POISONS  181 

apparently  not  poisonous  for  mammals,  except  the  "  cross 
spider "  (Epeira  diademd),  which  has  since  been  thoroughly 
studied  by  him  and  by  Sachs.1  In  these  spiders  also  the  poison 
is  found  throughout  the  body.  It  resembles  the  snake  venoms 
strikingly,  according  to  Sachs,  for  it  contains  a  powerful  hemo- 
lysin  which  he  calls  "  arachnolysin,"  acting  very  differently 
with  different  sorts  of  blood,  and  destroyed  by  heating  at 
70°-72°  for  forty  minutes.  Only  such  blood  is  hemolyzed  as 
is  able  to  bind  the  poison  in  the  stroma  of  the  red  corpuscles. 
By  immunizing  a  guinea-pig  Sachs  succeeded  in  securing  an 
antitoxin  of  some  strength.  The  discovery  of  this  hemolysin 
explains  Robert's  observation  of  hemoglobin,  methemoglobin, 
etc.,  in  the  urine  of  persons  bitten  by  spiders. 

Von  Fiirth  considers  that  the  bite  of  the  historically  famous 
Italian  tarantula  is  able  to  cause  no  more  than  local  inflamma- 
tion, and  Robert  found  that  the  entire  extract  of  six  Russian 
tarantulas  (which  are  supposed  to  be  more  poisonous  than  the 
Italian)  caused  no  symptoms  when  injected  into  a  cat. 

In  all  probability  the  other  poisonous  spiders  possess  toxic 
substances  allied  to  those  of  the  venoms,  with  hemolytic, 
agglutinative,  and  neurotoxic  products,  Sachs'  studies  indicating 
the  general  similarity  of  all  the  zootoxins. 

CENTIPEDES 

Undoubtedly  the  severity  of  centipede  poisoning  has  been 
greatly  exaggerated,  the  results  being  usually  limited  to  local 
inflammation,  frequently  spreading  some  distance  in  an  ery- 
sipelas-like manner.  An  authentic  case  of  fatal  poisoning  of 
a  child  four  years  old  by  a  centipede  (Scolopendra  heros)  has 
been  reported  from  Texas  by  G.  Linceicum,2  death  resulting 
five  to  six  hours  after  the  bite  was  received.  Besides  the  local 
pain  and  inflammation,  vomiting  was  marked,  occurring  also  in 
five  other  non-fatal  cases. 

Centipedes  secrete  their  poison  in  relatively  large  glands, 
which  discharge  at  the  apices  of  a  pair  of  specialized  claws  that 
take  the  place  of  the  first  pair  of  legs.  The  nature  of  this 
poison  seems  not  to  have  been  investigated.  Numerous  chemical 
substances  are  described  as  secreted  by  other  glands  of  these 
animals,  including  prussic  acid  and  a  camphor-like  matter  (see 
v.  Furth). 

1  Hofmeister's  Beitr.,  1902  (2),  125. 

2  Amer.  Jour.  Med.  Sci.,  1866  (52),  575. 


182  PHYTOTOXINS  AND  ZOOTOXISS 

BEE  POISON 

Bee  poison  has  been  better  studied  than  most  insect  poisons, 
beginning  with  the  work  of  Paul  Bert  (1865).  It  is  secreted 
by  the  glands  into  a  small  poison  sac,  and  stored  up  until  ejected. 
Cloez  found  that  bee  poison  was  precipitated  by  ammonia, 
tannin,  and  platinic  chloride,  and  Langer  proved  it  to  be  a  non- 
volatile organic  base.  As  excreted,  it  is  acid,  contains  30  per 
cent,  of  solids,  and  one  honey-bee  secretes  0.0003-0.0004  gm. 
It  contains  formic  acid  and  much  proteid,  but  it  has  been 
stated  that  the  poison  is  proteid-free,  and  is  not  destroyed  by 
heat  (100°),  weak  acids,  or  alkalies.  On  the  other  hand,  it  is 
said  to  be  destroyed  by  proteolytic  enzymes,  which  would  indicate 
that  it  is  of  proteid  nature.  Hemolysis  is  produced  both  in  vitro 
and  in  vivo  with  all  sorts  of  blood,  but  to  very  different  degrees, 
thus  resembling  spider  toxin.  Locally  bee  poison  causes 
necrosis,  with  marked  hyperemia  and  edema.  A  4500  gm. 
dog  was  killed  by  intravenous  injection  of  6  c.c.  of  a  1 .5  per 
cent,  solution  of  pure  poison  (Langer1). 

Immunity  is  undoubtedly  possible,  for  bee-keepers  frequently 
show  a  great  decrease  in  susceptibility.  On  the  other  hand, 
abnormally  great  susceptibility  is  frequently  seen,  some  cases 
of  fatal  poisoning  having  been  observed.2 

Ants  also  produce  formic  acid,  a  fact  so  well  known  that  it 
has  come  to  be  considered  that  this  is  the  source  of  their  toxicity. 
Yon  Furth,  however,  suggests  the  probability  that  ant  poison, 
like  that  of  the  bees,  owes  its  chief  effects  to  other  more 
complex,  unknown  poisons. 

POISONS  OF  DERMAL  GLANDS  OF  TOADS  AND  SALAMANDERS 

It  has  been  known  for  centuries  that  toads  produce  poisonous 
substances,  Par6  in  1575  having  discoursed  interestingly,  if 
inaccurately,  on  this  topic.  Numerous  studies  have  been  made 
of  these  poisons,  which  are  secreted  by  the  dermal  glands  and 
therefore  cannot  be  used  for  poisoning  either  prey  or  enemies 
(except  those  that  feed  upon  them)  ;  the  most  extensive  study 
being  that  of  Faust.3  He  isolated  two  constituents,  apparently 
the  same,  in  different  species  of  toads ;  one,  which  he  called 
bufotalin,  is  very  active,  resembling  the  digitalis  group  ;  the 
other,  bufonin,  is  much  less  active.  Bufonin  is  neutral  in 

1  Arch.  exp.  Path.  u.  Pharm.,  1896  (38),  381 ;  Arch,  internal.  Pharmac. 
et  Ther.,  1899  (6),  181. 

2  Hospitalstidende,  1905,  No.  27. 

3  Arch.  f.  exp.  Path.  u.  Pharm.,  1902  (47),  279.      Complete  bibliography 
and  review. 


POISONS  OF  TOADS  AND  SALAMANDERS  ]  83 

reaction,  soluble  in  warm  alcohol,  but  slightly  in  cold.  Analysis 
indicates  an  empirical  formula  of  C17H27O,  which  is  probably 
but  half  the  molecular  formula.  It  probably  is  the  cause  of 
the  milky  appearance  of  the  dermal  secretion.  Bufotalin  seems 
to  be  C34H46O10,  is  acid  in  reaction,  soluble  in  chloroform  and 
alcohol,  but  not  in  petroleum  ether.  Subcutaneous  injection  of 
2.6  mg.  bufotalin  killed  a  dog  (weighing  4  kg.)  in  four  to  five 
hours ;  given  by  mouth  it  causes  much  vomiting  and  diarrhea, 
so  that  large  doses  are  not  fatal.  It  causes  much  local  irritation 
when  applied  to  mucous  membranes,  but  produces  no  marked 
changes  at  the  site  of  injection.  The  eifects  on  the  circulation 
resemble  in  all  respects  those  of  the  digitalis  group  ;  bufonin 
acting  similarly  but  much  weaker  than  bufotalin.  Bufotalin 
seems  to  be  derived  from  bufonin  by  oxidation,  and  the  latter 
is  quite  similar  to  cholesterin,  apparently  having  the  following 
formula  :  HO-H26C17-C17H26-OH. 

Phisalix  and  Bertrand  l  have  found  poison  in  the  blood  of 
toads  similar  to  that  of  the  glands.  The  hemolytic  property 
observed  by  Pugliese  2  may  be  due  to  the  acidity  of  the  dermal 
secretion.  The  poisons  of  different  species  seem  to  be  quite  the 
same  in  all  (Faust). 

Salamanders  also  produce  poisonous  secretions  in  their 
dermal  glands,  which  have  been  studied  especially  by  Faust,3 
and  earlier  by  Zalesky,4  who  isolated  an  inorganic  base  which 
he  named  samandarin.  Faust  describes  samandarin  as  first 
stimulating  and  then  paralyzing  the  automatic  centers  in  the 
medulla.  The  poison  resembles  the  alkaloids,  having  the 
formula  C26H40N2O,  and  produces  death  in  doses  of  0.7-0.9 
mg.  per  kilo  (dogs)  with  respiratory  failure.  Immunization  of 
rabbits  was  practically  impossible.  A  second  alkaloid,  saman- 
daridin  (C20H31NO)  is  also  present  in  even  greater  quantities 
than  the  samandarin,  and  differs  only  in  being  we'aker. 

Bert 5  and  also  Dutartre  6  have  also  described  a  digitalis-like 
poison  in  the  secretion  of  the  dermal  glands  of  frogs. 

It  is  evident  that  all  of  these  poisons  are  quite  distinct  from 
the  venoms,  and  from  the  true  toxins,  apparently  being  simple 
chemical  compounds  not  related  to  the  proteids  and  not  capable 
of  causing  immunization.  The  same  is  true  of  caniharidin,  which 
is,  according  to  Meyer,7  an  acid  with  the  following  formula : 

1  Arch.  d.  physiol.  norm,  et  path.,  1893  (5),  511. 

2  Archivio  di  farm,  e  terap.,  1894  (2),  321 ;  Arch.  ital.  de  Biol.,  1895  (22),  79. 

3  Arch,  exper.  Path.  u.  Pharm.,  1898  (41),  229  (literature) ;  1900  (43),  84. 
*  Hoppe-Seyler's  Med.  Chem.  Untersuch.,  1866,  p.  85. 

5  Compt.  Kend.  Soc.  Biol.,  1885,  p.  524.  6  Ibid.,  1890,  p.  199. 

7  Lit.  given  by  Faust,  "  Die  tierischen  Gifte,"  p.  210. 


184  PHYTOTOXINS  AND  ZOOTOXINS 


CH 

/ 


o 


POISONOUS  FISH  i 

There  are  numerous  fish,  especially  in  tropical  waters,  which 
defend  themselves  by  injecting  poisons  into  their  enemies.  This 
is  accomplished  by  spines,  to  which  are  attached  poison  glands. 
Dunbar-Brunton 2  has  described  two  such  fish  (Trachinis  draco 
and  Seorpcena  scorphd)  of  Mediterranean  waters.  Wounds  by 
these  spines  cause  in  animals  intense  local  irritation  and  edema 
and  paralysis  of  the  part,  followed  by  gangrene  about  the  site 
of  the  wound ;  in  fatal  poisoning  death  occurs  in  from  one  to 
sixteen  hours,  with  general  paralysis.  The  sufferings  of  persons 
so  poisoned  are  said  to  be  extreme,  and  death  may  occur  either 
directly  from  the  poison  or  later  from  sepsis  following  the  local 
gangrene.  Presumably  this  poison  is  not  dissimilar  to  that  of 
the  snakes  ;  it  probably  is  not  an  alkaloid,  as  Dunbar-Brunton 
suggests.  It  affects  chiefly  the  heart,  according  to  Pohl.3 

Several  other  fish  secrete  poison  in  glands  attached  to  long 
spines,  one  of  the  most  poisonous  being  Synanceia  brachio,  which 
is  known  to  have  caused  fatal  intoxication  in  several  instances. 
Only  the  Murcenidce  seem  capable  of  poisoning  by  biting  ;  they 
have  a  well -developed  poison  apparatus  on  the  gums,  but  nothing 
is  known  concerning  the  poisons  they  produce. 

Many  fish  develop  poisonous  ptomai'ns  remarkably  soon  after 
death,  especially  in  tropical  climates,  so  that  a  fish  that  is 
perfectly  wholesome  if  eaten  immediately  after  being  caught 
may  be  very  poisonous  if  kept  but  a  few  hours.  There  is  a 
decided  difference  in  fish  of  different  varieties  in  this  respect, 
so  that  some  cannot  be  safely  marketed. 

There  are  also  other  fish  whose  bodies,  even  when  perfectly 
fresh,  contain  very  powerful  poisons.  Savtschenko,4  in  his 
elaborate  atlas  of  the  poisonous  fish,  describes  a  number  of  cases 
of  poisoning  by  the  famous  "parrot  fish"  of  Japan  (Tetrodon^, 
in  which  the  poison  seems  to  be  developed  and  contained  in  the 
ovaries  and  eggs,  and  therefore  the  degree  of  toxicity  varies 

1  Full  discussion  and  literature  given  by  Faust.  "Tierische  Gifte,"  p.  134. 

2  Lancet,  1896  (ii),  600. 

3  Prager  med.  Woch.,  1893  (18),  31. 

4  "Atlas  des  Poissons  Veneneux,"  St.  Petersburg,  1886  (literature). 


ZOOTOXINS  185 

with  the  season  of  the  year  in  which  the  fish  is  taken.  Poisoning 
by  these  fish  is  very  violent,  the  symptoms  appearing  very 
soon,  and  the  cases  are  divided  into  two  groups  by  Savtschenko, 
as  .the  algid,  or  choleriform,  and  the  gastro-intestinal  type.  The 
symptoms  of  the  algid  form  appear  almost  immediately  after 
eating  the  fish,  and  consist  of  pain  in  the  stomach,  with  great 
fear  and  distress  ;  soon  diarrhea  and  vomiting  set  in,  with 
cramps  in  the  arms  and  legs ;  this  terminates  in  collapse,  coma, 
and  death  from  either  respiratory  or  cardiac  paralysis.  The 
entire  course  of  the  process  may  be  but  ten  to  twenty  minutes, 
or  it  may  be  as  many  hours.  On  account  of  the  localization 
of  the  poison  in  the  eggs  and  ovaries  not  all  persons  who  eat 
the  fish  are  poisoned,  and  not  all  who  are  poisoned  receive  a 
fatal  dose.  In  the  gastro-intestinal  form  the  symptoms  appear 
later,  consist  chiefly  of  gastro-intestinal  disturbances  resembling 
more  closely  ptomam  poisoning,  and  the  prognosis  is  not  so  bad 
as  in  the  algid  form. 

The  pathological  anatomy  of  this  form  of  poisoning  has  not 
been  carefully  studied,  but  no  characteristic  or  striking  ana- 
tomical changes  have  been  noted  in  the  bodies  examined. 
Tahara1  has  described  a  crystalline  body,  tetrodonin,  and  a 
toxic  acid,  tetrodonie  acid,  which  are  highly  toxic ;  these  were 
isolated  from  the  ovaries  of  Tetrodon.2 

In  this  connection  may  be  mentioned  the  peculiar  erysipelas- 
like  lesions  caused  by  bites  of  crabs,  which  indicates  the  forma- 
tion of  some  toxic  product  by  these  crustaceans.  Gilchrist3 
obtained  a  history  of  bites  or  injuries  by  crabs  in  323  of  329 
cases  of  "  erysipeloid." 

EEL  SERUM 

In  18884  Mosso  studied  the  toxic  properties  of  eel  serum, 
which  he  found  was  extremely  poisonous  for  experimental  ani- 
mals, 0.1  to  0.3  c.c.  per  kilo  being  fatal  for  rabbits  and  dogs 
in  a  few  minutes  if  intravenously  injected  ;  introduced  into  the 
stomach  it  is  not  toxic.  The  poisonous  principle  he  called 
ichthyotoxin.  Death  results  from  respiratory  failure  with  large 
doses ;  small  doses  lead  to  cachexia  and  death  after  a  few  days. 
The  coagulability  of  the  blood  is  greatly  reduced.  Kossel 5 
found  histological  changes  in  the  central  nervous  system  in  such 
animals,  that  resembled  the  lesions  of  tetanus.  He  succeeded 

1  Eef.  in  Maly's  Jahresber.,  1894  (24),  450. 

2  Arch.  exp.  Path.  u.  Pharm.,  1890  (26),  401  and  453. 

3  Jour.  Cutaneous  Diseases,  November,  1904. 

4  Arch.  Ital.  de  Biol.,  1888  (10),  141 ;  1889  (12),  229. 
6Berl.  klin.  Woch.,  1898  (35),  152. 


186  PHYTOTOXINS  AND  ZOOTOXINS 

in  securing  an  active  antitoxin  which  neutralized  the  strongly 
hemolytic  action  of  eel  serum  in  vitro,  and  also  prevented  fatal 
effects  in  animals.  Camus  and  Gley l  have  studied  the  physio- 
logical action  of  eel  serum  and  found  it  strongly  hemolytic,  and 
also  apparently  neurotoxic.  The  toxicity  is  destroyed  by  heat- 
ing to  58°  for  fifteen  minutes.  By  immunization  an  antitoxic 
serum  can  be  obtained  which  neutralizes  the  eel  toxin  com- 
pletely. Tchistovitch 2  secured  antitoxic  serum,  which  acted 
also  as  a  precipitin  for  eel  serum.  De  Lisle 3  found  that  eel 
serum  does  not  act  like  an  amboceptor,  since  after  heating  it 
cannot  be  reactivated  with  fresh  serum,  and  it  seems,  therefore, 
to  be  different  from  snake  serum  in  its  structure. 

1Arch.  internal,  d.  Pharm.,  1899  (5),  247. 

2  Ann.  Inst.  Pasteur,  1899  (13),  406. 

3  Jour,  of  Med.  Kesearch,  1902  (8),  396. 


CHAPTER    IX 
HEMOLYSIS  AND  SERUM  CYTOTOXINS 

CYTOTOXINS 

JUST  as  precipitins  can  be  obtained  for  proteids  derived  from 
other  sources  than  bacterial  cells,  so  also  upon  immunizing  an  ani- 
mal against  various  types  of  cells  other  than  bacteria,  substances 
appear  in  its  serum  that  exercise  a  destructive  effect  upon  the 
type  of  cells  injected.  In  other  words,  the  reactions  of  animals 
to  infection  are  not  specially  devised  for  combating  bacteria 
and  their  products,  but  can  be  equally  exerted  against  non- 
bacterial  cells  and  their  products.  It  may  be  stated  as  a 
general  law  that  a  certain  degree  of  immunity,  accompanied  by 
the  appearance  of  specific  "antibodies"  in  the  serum,  may  be 
obtained  by  injecting  any  sort  of  foreign  cell  or  proteid  sub- 
stance into  an  animal ;  but  that  such  immunity  cannot  be 
obtained  unless  the  injected  material  is  of  a  proteid  nature  or 
very  closely  related  to  the  proteids,  e.  g.,  enzymes  and  toxins. 
In  the  case  of  soluble  proteids,  as  before  mentioned,  the  anti- 
bodies show  their  effects  by  precipitating  them,  with  agglutina- 
tion of  the  particles  into  flocculi ;  in  the  case  of  cells,  whether 
bacterial  or  tissue  cells,  the  antibodies  cause  agglutination  and 
loss  or  impairment  of  vitality.  This  injury  may  be  manifested 
by  loss  of  motion  in  motile  cells  (bacteria,  spermatozoa,  ciliated 
epithelium)  or  by  solution  of  their  contents  (bacteriolysis, 
erythrocytolysis,  leucocytolysis,  etc.),  or  by  cell  death  without 
marked  morphological  alterations  (B.  typhosus,  spermatozoa). 
If  we  inject  red  corpuscles,  leucocytes,  spermatozoa,  renal  epi- 
thelium, or  any  other  foreign  cell,  the  reaction  is,  therefore,  as 
specific  as  it  is  if  we  inject  bacteria,  and  of  exactly  the  same 
nature.  Therefore,  all  that  has  been  said  previously  concerning 
bactericidal  substances  and  agglutinins  can  be  transposed  to 
apply  to  immunity  against  tissue  cells.  As  a  matter  of  fact, 
however,  the  transposition  is  generally  made  in  the  other  direc- 
tion, for  red  corpuscles  are  much  easier  cells  to  study  than  bac- 
teria, because  their  laking  gives  prompt  and  readily  recognized 
evidence  that  the  toxic  serum  has  brought  about  changes. 
Much  of  our  knowledge  of  bactericidal  serum  has  been  obtained 
through  studies  of  the  mechanism  of  erythrocytolysis,  the  results 

187 


188  HEMOLYSIS  AND  SERUM  CYTOTOXINS 

of  which  have  then  been  applied  to  the  subject  of  bacteriolysis. 
Both  on  this  account,  therefore,  and  because  solution  of  red 
corpuscles  is  of  itself  an  important  process  in  many  intoxica- 
tions and  diseases,  the  subject  is  of  great  theoretical  and  practi- 
cal importance. 

HEMOLYSIS1  OR  ERYTHROCYTOLYSIS 

In  hemolysis  the  essential  phenomenon  consists  in  the  escape 
of  the  hemoglobin  from  the  stroma  of  the  corpuscles  into  the 
surrounding  fluid.  As  it  is  not  exactly  known  in  what  way 
the  stroma  holds  the  hemoglobin  normally,  whether  purely 
physically  or  in  part  chemically,  or  whether  the  stroma  consists 
of  a  spongioplasm  or  a  sac-like  membrane,  or  both,  the  ultimate 
processes  that  permit  the  escape  of  the  hemoglobin  are  not 
finally  solved.  However,  the  agents  by  which  the  escape  is 
brought  about  are  well  known  and  extensively  studied,  and 
they  are  found  to  be  of  extremely  various  natures.  They  may 
be  roughly  classified  as :  (1)  known  physical  and  chemical 
agents ;  (2)  unknown  constituents  of  blood-serum ;  (3)  bac- 
terial products ;  (4)  certain  vegetable  poisons ;  (5)  snake  venoms. 

HEMOLYSIS  BY  KNOWN  CHEMICAL  AND  PHYSICAL  AGENCIES 

The  Mechanism  of  Hemolysis. — If  distilled  water  is 
added  to  corpuscles  of  any  kind,  osmotic  changes  are  bound  to 
occur,  since  within  the  cells  are  abundant  salts,  soluble  in  water, 
which  will  begin  to  diffuse  outward  in  an  attempt  to  establish 
osmotic  equilibrium  between  the  corpuscles  and  the  surrounding 
fluid.  Conversely,  water  enters  the  corpuscles  at  the  same  time, 
and  accumulating  there  leads  to  swelling  until  such  injury  has 
been  produced  as  permits  the  hemoglobin  to  escape  and  enter 
the  surrounding  fluid.  Before  this  occurs  the  fluid  is  opaque 
because  of  the  obstruction  to  light  offered  by  the  red  cells,  but 
on  the  completion  of  hemolysis  the  fluid  becomes  transparent. 
The  stroma  now  settles  to  the  bottom,  while  the  hemoglobin 
diffuses  into  the  fluid,  making  it  red,  but  perfectly  transparent. 
This  process  has  long  been  known  as  the  "  laking "  of  blood, 
and  is  essentially  the  condition  present  in  all  forms  of  hemolysis. 
That  the  hemoglobin  escapes  only  through  injury  of  the  stroma 
and  not  through  simple  osmotic  diffusion  is  shown  by  the  fact 
that  if  salt  solution  of  the  same  concentration  as  normal  serum 
is  used  instead  of  distilled  water,  no  such  escape  of  hemoglobin 

1  Through  usage  this  term  has  been  limited  to  the  solution  of  the  red  cor- 
puscles, which  is  more  accurately  described  by  the  term  erythrocytolysis.  For 
bibliography  see  Sachs,  Ergebnisse  der  Pathol.,  1902  (7),  714. 


HEMOLYSIS  OR  ERYTHROCYTOLYSIS  189 

occurs.  As  hemoglobin  is  perfectly  soluble  in  the  salt  solution, 
it  should  pass  out  if  it  diffused  as  do  the  salts.  Since  there  is 
no  escape  of  hemoglobin  in  such  a  salt  solution,  it  is  evident 
either  that  the  stroma  is  not  permeable  to  hemoglobin,  or  else 
the  hemoglobin  is  in  some  way  attached  to  or  combined  with 
the  stroma.  Again,  if  the  corpuscles  are  placed  in  a  solution  of 
salt  more  concentrated  than  their  own  fluids,  water  escapes  and  the 
corpuscles  shrink ;  as  no  hemoglobin  escapes  with  the  water,  it 
is  evident  that  the  stroma  is  not  permeable  to  hemoglobin  when 
intact.  Because  of  the  resemblance  of  the  process  of  hemolysis 
to  the  rupture  of  plant  cells  with  escape  of  their  contents  when 
they  are  placed  in  distilled  water,  it  might  be  assumed  that 
hemolysis  is  largely  a  physical  matter,  but  there  are  many  indi- 
cations that  chemical  changes  must  be  involved.  For  example, 
if  a  red  corpuscle  in  an  isotonic  solution  is  cut  into  pieces,  the 
hemoglobin  does  not  escape,  indicating  that  its  structure  is  quite 
dissimilar  to  that  of  the  simple  vegetable  cell,  and  that  there  is 
some  union  of  stroma  and  of  hemoglobin  other  than  a  physical 
union.1 

Repeated  alternate  freezing  and  thawing  is  another  physical 
means  of  bringing  on  hemolysis.  Heating  to  62° -6 4°  C.  causes 
hemolysis  of  mammalian  corpuscles ;  in  cold-blooded  animals 
this  seems  to  occur  at  a  slightly  lower  temperature. 

Some  chemical  agents  are  capable  of  liberating  hemoglobin, 
even  when  the  corpuscles  are  in  isotonic  solutions.  The  ordi- 
nary salts  of  serum,  of  course,  do  not  have  this  property,  but 
ammonium  salts  are  strongly  hemolytic.  The  chemical  agents 
that  dissolve  red  corpuscles  seem  to  be  those  that  have  the  power 
of  penetrating  the  stroma.  Ammonium  salts  and  urea  penetrate 
the  corpuscles  freely  and  causes  hemolysis.  Sugar  and  NaCl 
seem  not  to*  penetrate  the  corpuscles,  and  therefore  do  not  pro- 
duce hemolysis.  Of  the  permeating  substances,  there  seem  to  be 
two  types  :  one,  like  urea,  does  not  produce  hemolysis  when 
in  a  solution  of  NaCl  isotonic  with  the  serum  ;  the  other,  like 
ammonium  chloride,  is  not  prevented  from  producing  hemolysis 
by  the  presence  of  JSaCl.2 

1  Stewart  (Jour,  of  Physiol.,  1899  (24),  211)  found  that  in  hemolysis  by 
physical  means  or  under  the  influence  of  serums,  there  is  no  marked  increase 
in  the  electrical  conductivity,  but  hemolysis  by  saponin  and  by  water  causes 
an  increase  of  conductivity,  presumably  because  of  the  escape  of  electrolytes. 

2  Hamburger,  in  his  book,  "  Osmotischer  Druck  und  lonenlehre,"  reviews 
exhaustively  the  physical  chemistry  of  hemolysis.     The  following  is  his  sum- 
mary of  the  permeability  of  red  corpuscles  by  various  substances : 

Organic  Substances. — (a)  Impermeable  for  sugars;  namely,  cane-sugar,  dex- 
trose, lactose,  also  arabit  and  mannit.  (b)  Permeable  for  alcohols,  in  inverse 
proportion  to  the  number  of  hydroxyl  groups  that  they  contain ;  also  for  aide- 


190  HEMOLYSIS  AND  SERUM  CYTOTOXINS 

All  these  agents  seem  to  effect  hemolysis  by  acting  on  the 
stroma,  for  when  the  stroma  of  corpuscles  hardened  in  formalin 
has  its  lecithin  and  cholesterin  removed  with  ether,  saponin,  a 
powerfully  hemolytic  substance,  seems  to  have  no  effect.  The 
action  of  saponin  and  of  many  other  hemolytic  agents  can  be 
prevented  by  the  presence  of  cholesterin  in  excess,  suggesting 
that  it  is  this  constituent  of  the  stroma  that  is  affected.1 

The  fact  that  chloroform,  ether,  bile  salts,  and  amyl  alcohol 
will  cause  laking  is  probably  intimately  connected  with  the  fact 
that  lecithin  and  cholesterin,  important  constituents  of  the  stroma, 
are  both  soluble  in  these  substances.2  Arseniuretted  hydro- 
gen, when  inhaled,  causes  intravascular  hemolysis,  and  there  are 
many  other  drugs  and  chemicals  with  the  same  property,  among 
which  may  be  mentioned  nitrobenzol,  nitroglycerin,  and  the 
nitrites,  guaiacol,  pyrogallol,  acetanilid,  and  numerous  aniline 
compounds.  Probably  the  hemolysis  produced  by  autolytic 
products  belongs  in  this  category.3  The  bile  acids  and  their 
salts  will  also  produce  hemolysis,  as  seen  in  jaundice.  Sodium 
bicarbonate  solutions  of  one  or  two  per  cent,  are  hemolytic  for 
some  varieties  of  corpuscles,  but  0.1  per  cent.  Na2CO3  and 
NaHCO3  do  not  cause  hemolysis. 

Leucocytes  are  dissolved  by  some  of  these  agents,  particularly 
the  bile  salts,  although  they  are  affected  by  no  means  so  rapidly 
or  so  much  as  are  the  erythrocytes.  There  seems  to  be  no- 
relation  between  the  erythrolytic  and  leucolytic  powers  of  these 
substances.  Water  causes  swelling,  with  solution  of  the  granules 
in  time,  and  the  same  is  true  of  ammonium-chloride  solutions. 

HEMOLYSIS  BY  SERUM 

Normal  blood-serum  of  many  animals  causes  hemolysis  to 
greater  or  less  degree  when  mixed  with  red  corpuscles  of  another 
species  of  animal,  and  this  property  can  be  greatly  increased  by 
immunizing  the  animal  with  red  corpuscles  in  the  usual  way. 

hydes  (except  paraldehyde),  ketones,  ethers,  esters,  antipyrin,  amides,  urea, 
urethan,  bile  acids  and  their  salts,  (c)  Slightly  permeable  for  neutral  amino- 
acids  (glycocoll,  asparagin,  etc.). 

Inorganic  substances,  not  including  the  salts  of  the  fixed  alkalies,  (a)  Com- 
pletely impermeable  for  the  cations  Ca,  Sr,  Ba,  Mg.  (6)  Permeable  for  NH4  ions, 
for  free  acids  and  alkalies. 

1  Kansom,  Deut.  med.  Woch.,  1901  (27),  194;  Robert,  "  Saponinsubstan- 
zen,"  Stuttgart,  1904;  Abderhalden  and  La  Count,  Zeit.  exp.  Path.  u.  Ther., 
1905  (2),  199.    Noguchi  (Univ.  of  Penn.  Med.  Bull.,  1902  (15),  327)  found 
lecithin  without  this  property. 

2  See  Koeppe,  Pfliiger's  Arch.,  1903  (99),  33 ;  Peskind,  Amer.  Jour.  Phys., 
1904  (12),  184. 

3  Concerning  hemolysis  by  alcohols,  ketones,  etc.,  organic  acids,  and  essences* 
see  Vandevelde,  Bull.  Soc.  chim.  de  Belgique,  1903  (19),  288. 


HEMOLYSIS  OR  ERYTHROCYTOLYSIS  191 

This  hemolysis  occurs  both  in  the  test-tube  and  in  the  body,  in 
the  latter  case  causing  severe  anatomical  changes  or  even  death. 
In  all  respects  the  mechanism  of  hemolysis  by  serum  seems  to  be 
identical  with  that  of  bacteriolysis.  Two  substances  are  con- 
cerned, one,  the  amboceptor,  which  resists  heat  and  which  is 
increased  by  immunizing;  the  other,  complement,  which  is 
destroyed  at  55°  and  which  is  present  in  normal  serum.  In 
this  case  the  substances  may  be  referred  to  as  hemolytic  ambo- 
ceptors  and  hemolytic  complements.1 

In  spite  of  the  availability  of  these  particular  cytolytic  sub- 
stances for  study,  very  little  has  been  learned  of  their  exact 
nature  and  properties.  It  is  known  that  amboceptor  is  com- 
bined with  the  red  cells  in  a  certain  sense  quantitatively,  a  cer- 
tain amount  being  required  to  saturate  a  given  amount  of  cor- 
puscles so  that  they  will  all  be  hemolyzed  when  complement  is 
added ;  and  that  this  reaction  is  complete  in  less  than  fifteen 
minutes  at  45°.  What  change  this  addition  of  amboceptor 
brings  about  in  the  corpuscles  is  unknown.  It  has  also  been 
shown  that  at  0°  the  affinity  between  the  amboceptor  and  the 
corpuscle  is  greater  than  it  is  between  amboceptor  and  comple- 
ment, so  that  it  is  possible  at  this  temperature  to  remove  all  the 
amboceptor  from  a  serum  by  treating  it  with  red  corpuscles,  and 
thus  we  can  obtain  complement  free  from  amboceptor.  This 
experiment  also  shows  that  the  two  bodies  exist  side  by  side  in 
the  serum  without  combining,  and  that  combination  occurs  only 
after  the  amboceptor  has  become  united  to  the  erythrocyte. 

The  Atnboceptor. — Amboceptor  is,  as  a  rule,  destroyed 
by  heating  to  70°  or  higher.  Its  place  of  origin  is  unknown. 
Metchnikoff  holds  that  it  is  derived  chiefly  from  the  leucocytes, 
in  support  of  which  view  is  the  fact  that  leucocytes  dissolve  red 
corpuscles  after  ingesting  them  ;  however,  other  phagocytic  cells 
have  the  same  power,  particularly  endothelial  cells,  and  it  is  an 
open  question  whether  the  intracellular  digestion  of  engulfed  cells 
is  the  same  process  as  extracellular  hemolysis ;  probably  it  is 
not,  for  there  seem  to  be  more  disintegrative  changes  in  intra- 
cellular digestion  than  in  hemolysis.  Quinan 2  found  that  the 
diffusible  constituents  of  hemolytic  serum  played  no  role  beyond 
that  of  maintaining  osmotic  pressure.  He  was  unable,  however, 
to  localize  the  immune  body  in  any  of  the  proteid  constituents. 
Kyes  found  that  a  combination  of  hemolytic  amboceptor  of 
venom  and  lecithin  gave  no  biuret  reaction.  The  amboceptors 

1  Bang  and  Forssmann  (Hofmeister's  Beitr.,  1906  (8),  238)  do  not  accept 
the  prevailing  view. 

2  Hofmeister's  Beitr.,  1904  (5),  95. 


192  HEMOLYSIS  AND  SERUM  CYTOTOXINS 

of  normally  hemolytic  serum  seem  to  be  no  different  from  those 
in  immune  serum,  and  amboceptors  of  one  animal  can  combine 
with  complement  furnished  by  the  serum  of  an  entirely  different 
animal.  It  is  the  amboceptor  alone  that  gives  the  specific 
nature  to  the  reaction,  and,  as  is  the  case  with  all  other  immuni- 
zations, it  is  very  difficult  to  secure  antibodies  by  immunizing  an 
animal  with  blood  from  another  animal  of  its  own  species,  iso- 
hemolysins ;  and  impossible  to  secure  antibodies  for  its  own 
blood,  autohemolysins. 

Although  Bordet  and  other  French  observers  have  claimed 
that  the  union  between  amboceptor  and  corpuscle  is  physical 
and  not  chemical,  the  evidence  seems  to  point  the  other  way.1 
Probably  the  union  is  with  the  stroma  rather  than  with  the 
hemoglobin,  and  the  result  of  the  union  is  to  render  the  stroma 
permeable  to  the  hemoglobin,  or  to  separate  the  bonds  that 
unite  the  hemoglobin  to  the  stroma.  Mathes 2  contends  that 
red  corpuscles  cannot  be  dissolved  by  hemolytic  serum  or  by 
pancreatic  juice  until  after  they  have  been  killed ;  as  heated 
serum  does  not  kill  them,  this  is  presumably  done  by  the 
complement.  Corpuscles  that  have  been  killed  can  then  be 
dissolved  in  their  own  serum.  Levene3  tried  to  produce  hemo- 
lytic serums  by  immunizing  with  different  constituents  of  cor- 
puscles, using — (1)  pure  crystalline  hemoglobin  ;  (2)proteids  of 
the  stroma  soluble  in  salt  solutions  ;  (3)  an  extract  with  alcohol- 
ether;  and  (4)  an  extract  in  1.5  per  cent,  sodium  bicarbonate. 
Only  the  last  gave  positive  results,  and  the  serum  was  almost 
devoid  of  agglutinative  properties.  Injection  with  corpuscles 
that  had  been  digested  with  trypsin  gave  about  the  same  results 
as  alkaline  extracts  ;  corpuscles  digested  by  pepsin  gave  a  much 
weaker  serum  ;  in  neither  was  agglutination  obtained.  Accord- 
ing to  Bang  and  Forssmann  4  ethereal  extracts  of  red  corpuscles 
give  rise  to  production  of  hemolysins  on  immunization,  and  this 
"lysinogen"  substance  can  be  precipitated  with  acetone,  is  in- 
soluble in  alcohol,  is  not  destroyed  by  boiling,  and  gives  rise  to 
no  agglutinin.  Ford  and  Halsey 5  obtained  serum  with  both 
lytic  and  agglutinative  powers  by  injecting  either  the  stroma  or 
the  laked  blood  free  of  stroma ;  results  with  pure  hemoglobin 

1  Bang  and  Forssmann  (Hofmeister's  Beitr.,  1906  (8),  238)  suggest  that  the 
amboceptor  merely  renders  the  corpuscle  permeable  for  the  complement,  per- 
haps through  action  on  the  lipoid  membrane ;  the  complement  then  acts  directly 
upon  some  constituent  of  the  corpuscle,  without  the  amboceptor  acting  as  a 
combining  substance  in  any  way. 

2  Munch,  med.  Woch.,  1902  (49),  8. 

3  Jour.  Med.  Research,  1904  (12),  191. 

4  Hofmeister's  Beitr.,  1906  (8),  238. 

5  Jour.  Med.  Research,  1904  (11),  403. 


HEMOLYSIS  OR  ERYTHROCYTOLYSIS  193 

were  indefinite.  Stewart l  obtained  similar  results  by  immuniz- 
ing with  corpuscles  laked  by  physical  means,  by  serums,  or  by 
saponin.  According  to  Guerrini,2  nucleoproteid  obtained  from 
dog's  blood  will  give  rise  to  specific  hemolysins,  and  Beebe  has 
found  that  nucleoproteids  from  visceral  organs  do  not  have  this 
effect.  Levene's  alkaline  extracts  probably  also  contained 
nucleoproteids. 

The  Complement. — Hemolytic  complement  possesses  the 
same  properties  as  bacteriolytic  complement,  resembling  enzymes 
to  the  extent  that  it  is  susceptible  to  heat  and  causes  a  disinte- 
gration of  cells.  The  joint  action  of  amboceptor  and  complement 
is  strikingly  like  the  activation  of  trypsinogen  by  trypsin,  or  of 
glycolytic  enzyme  by  pancreatic  extract.  On  the  other  hand, 
hemolysis  by  serum  is  quite  different  from  the  effect  of  trypsin 
on  corpuscles,  as  trypsin  completely  disorganizes  the  hemo- 
globin and  destroys  the  stroma,  while  in  hemolysis  the  stroma 
and  hemoglobin  seem  to  be  merely  separated  from  one  another 
but  not  chemically  altered.  Again,  hemolysin  acts  quantitatively, 
although  that  may  be  due  to  a  difference  in  the  way  the  binding 
to  the  cell  occurs,  rather  than  in  the  method  of  action  of  the 
complement. 

Probably  complement  is  produced  in  leucocytes,  and  perhaps 
in  many  or  all  other  cells,  but  removal  of  the  spleen  does  not 
prevent  either  the  presence  of  complement  or  the  formation  of 
immune  bodies.  Although  the  serum  of  one  animal  may  com- 
plement the  immune  bodies  in  serum  of  several  other  varieties, 
and  also  produce  lysis  of  many  sorts  of  cells,  there  is  probably 
not  one  complement  that  does  all  the  complementing ;  Ehrlich 
and  others  have  proved  that  one  serum  may  contain  several  com- 
plements of  slightly  differing  natures.  It  is  also  known  that 
heat-resisting  substances  may  act  as  complement,  and  Kyes  has 
demonstrated  that  red  corpuscles  may  contain  within  themselves 
a  hemolytic  complement,  endocomplement.  For  cobra  poison 
lecithin  may  act  as  complement,  and  it  has  been  possible  to 
isolate  the  lecithin-venom  combination.3 

Antibodies  can  be  obtained  for  both  complement  and  hemo- 
lytic amboceptor  by  immunizing  against  serum  containing  them, 
and  in  many  serums  antihemolysins  exist  normally.  Against 
certain  vegetable  hemolysins  this  antihemolytic  action  is  very 
strong  (Kobert).  Antihemolysins  are  generally  anticomple- 
ments,  but  in  a  number  of  instances  anti-amboceptors  have  been 
obtained. 

1  Amer.  Jour,  of  Physiol.,  1904  (11),  250. 

2  Kiv.  crit.  di  clin.  med.,  1903  (4),  561. 

3  Kyes,  Berl.  klin.  Woch.,  1903  (40),  957. 

13 


194  HEMO LYSIS  AND  SERUM  CYTOTOXINS 

Hemagglutinin. — Agglutination  of  red  corpuscles  occurs 
under  the  influence  of  immune  serum  as  well  as  under  the  influ- 
ence of  some  normal  serums.  In  all  respects  the  principles 
seem  to  be  the  same  as  those  described  for  bacterial  aggluti- 
nation. Agglutination  occurs  at  much  lower  temperatures  than 
hemolysis,  and  also  is  not  checked  by  heating  the  serum  to  55°; 
hence  it  is  possible  to  observe  hemagglutination  independent  of 
hemolysis.  Serums  may  contain  hemagglutinins  and  not  be 
hemolytic  ;  the  reverse  is  also  true.  As  agglutination  occurs  in 
corpuscles  that  have  been  fixed  in  formalin  or  sublimate,  it  is 
probably  not  the  proteids  that  are  affected,  but  some  other  of 
the  ingredients  of  the  stroma,  of  which  lecithin  and  cholesterin 
seem  to  be  the  chief. 

Certain  vegetable  poisons  also  produce  agglutination  of  red 
corpuscles,  especially  ricin,  abrin,  and  crotin,  and  the  fact  that 
ricin  has  little  or  no  hemolytic  action  shows  the  independence 
of  the  processes.  Snake  venoms  contain  agglutinins,  destroyed 
by  heating  to  75°;  their  agglutinating  power  being  in  inverse 
ratio  to  their  hemolytic  power.  Corpuscles  agglutinated  by 
venoms  may  be  again  separated  by  potassium  permanganate 
solutions.1  Silicic  acid  and  certain  other  colloids  may  act  as 
agglutinins,  their  effects  bearing  a  relation  to  the  effects  of 
electrical  charges  upon  agglutination  of  bacteria  or  of  colloids 
(q.  V.).* 

Agglutination  of  the  corpuscles  during  life  may  be  of  some 
pathological  importance,  for  such  masses  of  agglutinated  cor- 
puscles may  readily  produce  capillary  thrombi  and  emboli, 
which,  if  wide-spread,  may  create  much  disturbance.  Many  bac- 
teria produce  substances  that  are  agglutinative  for  human  red 
corpuscles,  among  them  being  B.  typhosus,  pyocyaneus,  and 
staphylococcus.  Flexner3  has  found  in  typhoid  fever  thrombi 
that  seemed  to  be  composed  of  agglutinated  red  corpuscles, 
almost  free  from  fibrin  and  leucocytes.  Probably  many  of  the 
so-called  "  hyaline  thrombi "  found  frequently  in  infectious 
diseases  are  really  composed  of  agglutinated,  partly  hemolyzed 
red  corpuscles  (see  "  Thrombosis,"  Chap.  xi). 

HEMOLYSIS  BY  BACTERIA 

Both  pathogenic  and  non-pathogenic  bacteria  produce  hemo- 
lytic substances  that  are  excreted  into  the  fluids  in  which  they 
grow.  During  many  infectious  diseases  marked  hemolysis  occurs, 

1  See  Flexner,  Univ.  of  Penn.  Med.  Bull.,  1902  (15),  361  and  324. 

2  See  Landsteiner  and  Jagic,  Munch,  med.  Woch.,  1904  (51),  1185. 

3  Univ.  of  Penn.  Med.  Bull.,  1902  (15),  324;  Amer.  Jour.  Med.  Sci.,  1903 
(126),  202. 


HEMOLTSIS  BY  BACTERIA  195 

especially  in  those  diseases  accompanied  by  septicemia.  After 
death  the  hemoglobin  of  the  blood  goes  into  solution,  and  the 
resulting  staining  of  the  walls  of  the  blood-vessels,  and  later  of 
the  tissues  everywhere,  is  generally  familiar.  In  the  post- 
mortem hemolysis  probably  the  putrefactive  organisms  are  chiefly 
concerned,  although  it  is  marked  a  very  short  time  after  death 
in  many  cases  of  septicemia,  particularly  when  the  infecting 
organism  is  the  streptococcus,  and  here  probably  the  pathogenic 
organism  is  the  chief  cause  of  the  hemolysis.  The  hemolytic 
action  of  bacteria  can  be  studied  both  in  vitro  and  in  vivo. 
Among  the  best  known  are  tetanolysin,  pyocyanolysin,  typholy- 
sin,  staphylolysin,  and  streptocolysin,  as  they  have  been  termed. 
Of  these,  the  case  of  pyocyanolysin  is  questionable,  because  it 
has  been  described  as  resisting  heat  above  the  boiling-point,  and 
Jordan l  seems  to  have  proved  that  the  hemolysis  is  ascribable 
to  the  alkalinity  that  this  organism  produces  in  culture-media. 
Other  bacterial  hemolysins  are,  however,  destroyed  by  heat  at 
70°  C.  for  two  hours ;  but  they  are  altogether  different  from 
ordinary  cellular  hemolysins.  G.  Ruediger 2  shows  the  follow- 
ing differences  between  strep tocoly sin  and  the  hemolysins  of 
serum;  streptocolysin  is  not  destroyed  at  65°  C.  for  one-half 
hour,  and  therefore  is  different  from  complement.  When  de- 
stroyed by  heating  to  a  higher  point,  it  cannot  be  reactivated  by 
the  addition  of  complement,  thus  differing  from  intermediary 
body.  It  is  also  different  from  intermediary  body  in  that  it 
does  not  combine  with  corpuscles  at  0°  C.  ;  on  the  other  hand, 
it  does  combine  at  6°  C.,  but  does  not  exert  any  hemolytic 
effect  until  the  mixture  is  raised  to  a  higher  temperature.  This 
last  observation  indicates  that  the  streptocolysin  is  similar  in 
nature  to  the  toxins,  namely,  a  toxophore  group  and  a  hapto- 
phore  group.  In  other  words,  streptocolysin  is  simply  a  toxin 
for  red  cells,  and  unites  directly  to  the  cell  receptors  without 
the  intervention  of  any  intermediary  body.  As  a  similar  struc- 
ture has  been  shown  for  staphylolysin  and  tetanolysin,  it  is 
probable  that  the  bacterial  hemolysins  are  all  merely  toxins  with 
a  particular  affinity  for  red  cells.3 

Secondary   anemia   occurring  in   the   infectious    diseases    is 

1  Jour.  Medical  Research,  1903  (10),  31. 

2  Jour.  Amer.  Med.  Assoc.,  1903  (41),  962. 

3  Abbott  and  Gildersleeve  [Jour.  Med.  Research,  1903  (10),  42)  consider 
that  the  hemolysis  observed  with  some  bacterial  cultures  is  simply  proteolysis 
by  the  contained  enzymes. 

According  to  v.  Eisler,  (Wien.  klin.  Woch.,  1906  (19),  No.  23)  normal 
horse  serum  contains  two  substances  antagonizing  tetanolysin  and  staphylolysin. 
One  is  cholesterin,  the  other  is  precipitated  out  with  the  serum  globulin  and 
is  destroyed  by  peptic  digestion. 


196  HEMOLYS1S  AND  SERUM  CYTOTOXIXS 

probably  to  be  explained  largely  by  this  hemolytic  property  of 
bacterial  toxins.  Hemoglobinuria  may  also  be  produced  in  the 
same  way  in  some  instances.  Intravenous  injections  of  filtrates 
of  the  saprophyte,  B.  megatherium,  will  produce  hemoglobin- 
uria  in  guinea-pigs,  hence  hemolysis  is  not  an  exclusive  property 
of  pathogenic  bacteria. 

HEMOLYSIS  BY  VEGETABLE  POISONS 

A  number  of  plant  poisons  are  strongly  hemolytic,  and  some 
of  them  owe  much  of  their  toxicity  to  their  effect  on  the  erythro- 
cytes.  One  group  consists  of  the  bodies  often  called  "  vege- 
table toxalbumins, "  because  they  seem  to  be  proteids,  and 
includes  ricin,  abrin,  crotin,  and  robin.  Of  these,  crotin  and 
phallin  are  particularly  actively  hemolytic,  while  ricin,  abrin, 
and  robin  are  more  marked  by  their  agglutinating  action,  hem- 
olysis being  produced  only  by  relatively  large  doses.  Their 
effects  vary  greatly,  however,  according  to  the  species  of  animals 
whose  blood  is  used.  They  resemble  the  bacterial  toxins  in 
that  immunity  can  be  secured  against  them,  and  the  immune 
serum  will  prevent  their  hemolytic  action.  Heating  the  toxal- 
bumins to  65°  or  70°  does  not  destroy  the  hemolytic  or  agglu- 
tinating action  except  with  phallin,  but  100°  does.  The  action 
of  these  substances  is  not  like  that  of  the  enzymes,  in  that  it  is 
quantitative,  a  given  amount  acting  on  a  given  amount  of  cor- 
puscles to  which  it  is  bound.  Madsen  and  \Yalbum  l  observed 
that  red  corpuscles  had  the  power  of  dissociating  neutral  mix- 
tures of  ricin  and  antiricin,  the  ricin  entering  the  corpuscles 
from  which  it  could  be  recovered.2  (The  general  nature  and 
other  properties  of  these  substances  have  been  considered  under 
the  heading  of  "  Phytotoxins,  "  in  the  preceding  chapter.) 

Phallin,  from  Amanita  phalloides,  is  considered  by  Kobert  to  be  of 
albumose  nature,  a  "  toxalbumin,"  and  its  principal  effects  are  due  to 
its  hemolytic  action,  which  is  said  to  be  equal  to  or  stronger  than  that 
of  cyclamin  (Kunkel).  Ford3  found  the  hemolytic  principle  of  Amanita 
to  resemble  the  bacterial  hemolysins  in  acting  directly  upon  corpuscles 
without  the  presence  of  serum.  It  dissolves  all  varieties  of  erythrocytes, 
is  inactivated  at  65°  for  one-half  hour,  is  not  inhibited  by  cholesterin 
and  lecithin,  but  is  inhibited  by  serum  and  by  milk,  and  destroyed  by 
digestive  enzymes.  Immune  serum  neutralizes  this  hemolytic  property. 
Besides  the  hemolytic  poison,  phallin,  there  is  a  thermostable  poison 
which  is  strongly  toxic  but  not  hemolytic.4 

1  Cent.  f.  Bakt.,  1904  (36),  242. 

m  2  According  to  Pascucci  (Hofmeister's  Beitr.,  1905  (7),  457),  ricin  combines 
directly  with  lecithin,  the  compound  being  strongly  hemolytic. 

3  Jour.  Infect.  Diseases,  1906  (3),  191. 

4  See  Ford,  Jour.  Exp.  Med.,  1906  (8),  437. 


HEMOLYSIS  OR  ERYTHROCYTOLYSIS  197 

Saponin  Group. — Another  quite  distinct  group  of  vege- 
table hemolyzing  agents  consists  of  the  " saponin  substances"  l 
These  are  a  closely  related  group  of  glucosidex,  found  in  at  least 
46  different  families  of  plants,  and  they  are  strong  protoplasmic 
as  well  as  heraolytic  poisons.  They  differ  altogether  from  the 
true  toxins,  being  heat  resistant,  having  no  resemblance  to  pro- 
teids,  and  not  giving  rise  to  antibodies  on  immunization  of 
animals.2  The  degree  of  their  toxicity  is  not  directly  proportional 
to  their  hemolytic  activity  ;  they  seem  to  injure  chiefly  the  nerve- 
cells.  Apparently  hemolysis  is  brought  about  by  action  upon  the 
lipoids  of  the  red  corpuscles,  for  addition  of  cholesterin  to  saponin 
prevents  its  hemolytic  effect ; 3  lecithin  does  not  have  the  same 
property.4  Both  cholesterin  and  lecithin  combine  with  saponin, 
the  cholesterin  compound  being  quite  inert,  whereas  the  lecithin 
compound  is  both  hemolytic  and  toxic.  Cholesterin  is  also 
soluble  in  sapotoxin.  Normal  serum  seems  to  contain  an  anti- 
hem  oly  sin  for  saponin,  and  therefore  hemoglobin uria  is  not 
produced  by  all  saponins  on  intravenous  injection.  Careful 
immunization  leads  to  a  slight  increase  in  this  antihemolytic 
action  of  the  serum,  possibly  due  to  an  increased  formation  of 
cholesterin  (Kobert). 

A  study  of  the  toxicity  of  the  members  of  this  group  by 
Kobert 5  shows  that  in  general  they  have  similar  properties,  but 
that  minor  differences  exist  between  them.  All  cause  hemoly- 
sis, some  in  dilution  as  great  as  1  :  100,000.  Some  produce 
hemoglobinuria  when  injected  intravenously,  others  do  not. 
All  paralyze  the  heart,  but  the  injuries  to  the  central  nervous 
system  are  the  chief  cause  of  death.  Marked  local  changes  are 
produced  at  the  site  of  injection,  but  the  leucocytes  are  appar- 
ently not  injured,  although  sterile  suppuration  is  produced. 
There  is  a  period  of  latency  after  intravenous  injection  of  small 
doses — twenty-four  hours  or  more — before  the  appearance  of 
symptoms. 

SAPOTOXIN  is  one  of  the  most  actively  toxic  and  hemolytic 
products  of  quillaja. 

1  Complete  literature  on  saponin  given  by  Kobert,  "  Die  Saponinsubstanzen, " 
Stuttgart,  1904 ;  also  Kunkel,  "  Handbuch  der  Toxokologie,"  Jena,  1904. 

2  Saponins  are  characterized  by  their  ready  solubility  in  water  and  the 
foaming,  soapy  character  possessed  by  the  solution ;  hence  their  technical  appli- 
cations as  soap  bark,  etc.     Heated  with  dilute  acids  they  split  off  sugar ;  also 
when  acted  on  by  glucoside-splitting  enzymes   (from  spiders),  according  to 
Kobert.     Saponin  from  Quillaja  (soap-bark)  has  the  formula  C^H^O^  (Stiitz). 
Most  are  colloids,  but  some  crystallize. 

3  Ransom,  Dent.  med.  Woch.,  1901  (27),  194;  Madsen  and  Noguchi,  Cent, 
f.  Bakt,  1905  (37),  367. 

*  Noguchi,  Univ.  of  Penn.  Med.  Bull.,  1902  (15),  327. 
5  Arch.  exp.  Path.  u.  Pharm.,  1887  (23),  233. 


198  HEMOLYSIS  AND  SERUM  CYTOTOXINS 

CYCLAMIN  is  also  a  member  of  this  group  (derived  from 
Cyclamen),  and  is  said  to  be  the  most  active  of  all  as  a  hemolytic 
agent  (Tufanow). 

SOLANIN  l  is  obtained  from  all  parts  of  the  potato  plant, 
combined  with  malic  acid ;  it  is  found  particularly  in  young 
sprouts,  but  not  in  any  considerable  amounts  from  normal 
potatoes.2  Its  formula  is  unknown,  but  as  it  splits  up  into  an 
alkaloid  (solanidiri)  and  sugar  it  is  called  a  glyco-alkaloid.  In 
its  action  it  resembles  the  saponins,  being  a  powerful  proto- 
plasmic poison,  killing  bacteria,  and  hemolyzing  blood  in  very 
great  dilutions. 

A  number  of  hemolytic  poisons  are  obtained  from  poisonous 
mushrooms.  Best  known  of  these  is  : 

HELVELLIC  ACID,  from  Helvetia  esculenta,  which  has  the 
empiric  formula  C12H20Or3  Intravenously  injected  it  produces 
hemoglobinuria  and  icterus,  with  hemoglobin  infarcts  in  the 
kidneys  (Bostroem4 ). 

As  will  be  seen,  all  of  these  last-mentioned  vegetable  hemo- 
lytic agents  are  essentially  different  from  either  the  bacterial  or 
serum  hemolysins,  or  from  the  abrin,  ricin,  crotin,  or  robin 
group,  in  that  they  are  of  relatively  simple  chemical  composition, 
and  quite  unlike  proteids,  enzymes,  or  toxins.  The  manner  in 
which  they  cause  hemolysis  is  unknown,  but  from  their  relation 
to  saponin  it  is  probable  that,  like  it,  they  cause  injury  by  com- 
bining with  or  dissolving  the  lipoids  of  the  stroma  of  the 
corpuscles. 

HEMOLYSIS  BY  VENOMS5 

The  laking  of  blood-corpuscles  by  venoms  is  of  peculiar 
interest  from  the  standpoint  of  Ehrlich's  theory,  since  it  has 
been  demonstrated  by  Flexner  and  Noguchi 6  that  the  hemolytic 
principle  of  the  venoms  is  an  amboceptor.  As  venom  contains 
no  complement  this  has  to  be  furnished  by  the  blood,  and  so  in 
the  case  of  venom  poisoning  the  victim  furnishes  the  comple- 
ment that  destroys  its  own  corpuscles.  The  hemolytic  arnbo- 
ceptors  of  venom  seem  to  be  secreted  by  the  salivary  glands  of 

1  Literature,  see  Meyer  and  Schmiedeberg,  Arch.  f.  exp.  Path,  und  Pharm., 
1895  (36),  361;  Perles,  ibid.,  1890  (26),  88. 

2  See  Kunkel,  "  Handbuch  der  Toxokologie, "  p.  873. 

3  Boehm  and  Kiilz,  Arch.  exp.  Path.  u.  Pharm.,  1885  (19),  403. 

4  Deut  Arch.  klin.  Med.,  1883  (32),  209. 

5  General  review  of  literature  on  the  hemolytic  properties  of  animal  poi- 
sons given  by  Sachs,  Biochem.  Centralblatt,  1906  (5),  257. 

6  Jour.  Exper.  Med.,  1902  (6),  277;  Univ.  of  Penn.  Med.  Bull.,  1902  (14), 
438;  and  1902  (15),  345. 


HEMOLYSIS  BY  VENOMS  199 

the  reptiles  from  their  blood,  which  contains  almost  identical 
amboceptors,  differing  chiefly  in  that  they  can  combine  only 
with  the  complement  contained  in  snake  blood,  while  the  ambo- 
ceptors  of  venom  can  combine  with  the  complement  of  nearly 
all  sorts  of  blood.  Venoms  from  cobra,  rattlesnake,  moccasin, 
and  copperhead  possess  in  each  variety  intermediary  bodies 
(amboceptors)  that  seem  to  be  identical  in  nature,  although  they 
may  vary  in  quantity.  This  explains  the  rather  remarkable 
fact  that  serum  of  animals  immunized  against  cobra  poison, 
generally  called  antivenin,  will  neutralize  the  hemolytic  and 
many  of  the  other  properties  of  the  venom  of  rattlesnake, 
copperhead,  and  moccasin.  Antivenin  acts  as  an  anti-interme- 
diary body,  and  by  occupying  a  haptophore  group  of  the  ambo- 
ceptor,  prevents  its  completing  the  union  of  complement  and 
cell.  In  order  of  decreasing  hemolytic  power  for  mammalian 
corpuscles  come  venoms  from  cobra,  water  moccasin,  copper- 
head, and  rattlesnake.  These  venoms  are  also  agglutinative 
for  all  corpuscles  tried,  and  agglutination  will  occur  at  0°  C. 
Exposure  for  thirty  minutes  at  75°-80°  C.  destroys  the  agglu- 
tinating property.  In  general,  the  hemolytic  power  of  the 
venoms  for  different  sorts  of  corpuscles  varies  in  inverse  pro- 
portion to  its  agglutinative  power.  The  hemolytic  intermediary 
bodies  are  remarkably  resistant  to  heat,  suffering  but  slight  loss 
of  power  at  100°  C.  Red  corpuscles  of  the  frog  are  not  hemo- 
lized  by  venom,  and  those  of  necturus  (mud  puppy),  but  slightly, 
agreeing  with  the  known  resistance  of  cold-blooded  animals  to 
snake-bites. 

The  highly  hemolytic  cobra  venom  can  combine  with  comple- 
ments contained  within  the  red  corpuscles,  endocomplement,  and 
so  produce  hemolysis  in  the  absence  of  serum  complement. 
Kyes  has  shown  that  lecithin  may  be  the  constituent  of  red  cor- 
puscles that  acts  as  the  complement. 

Eel  serum  is  remarkably  hemolytic,  so  much  so  that  a  quan- 
tity of  0.1  c.c.  per  kilogram  of  body  weight  will  kill  a  rabbit 
or  guinea-pig  in  three  minutes  when  injected  intravenously. 
Heating  at  54°  C.  for  fifteen  minutes  destroys  the  hemolytic 
action,  and,  unlike  ordinary  serum  hemolysins  the  addition  of 
complement  does  not  restore  its  activity.  Animals  can  be 
immunized  against  this  serum.  Introduced  into  the  stomach  in 
ordinary  quantities  eel  serum  is  not  toxic.  It  can  be  dried  and 
redissolved  without  losing  its  activity,  but  acids  and  alkalies 
readily  destroy  it.  Mosso,  who  first  discovered  the  toxicity  of 
eel  serum,  called  the  unknown  active  principle  ichthyotoxin 
(see  preceding  chapter). 


200  HEMOLYSIS  AND  SERUM  CYTOTOXINS 

HEMOLYSIS  IN  DISEASE 

During  health  there  is  always  going  on  a  certain  amount  of 
destruction  of  red  corpuscles  that  have  outlived  their  usefulness  ; 
hence  in  disease  we  may  have  to  deal  with  either  an  alteration 
in  the  normal  processes  of  blood  destruction  or  the  introduction 
of  entirely  new  processes.  Although  the  place  and  manner  of 
normal  red  corpuscle  destruction  is  not  completely  known,  yet 
it  seems  probable  that  there  is  relatively  little  hemolysis  within 
the  circulating  blood.  When  a  red  corpuscle  becomes  damaged, 
it  seems  to  become  more  susceptible  to  phagocytosis,  and  it  is 
then  picked  out  of  the  blood,  chiefly  by  the  endothelial  cells  of 
the  sinuses  of  the  spleen,  hemolymph  glands,  and  bone-marrow. 
Within  these  cells  it  apparently  undergoes  hemolysis.  Eventu- 
ally, the  resulting  pigment  is  split  up  by  the  liver,  the  nou- 
ferruginous  portion  forming  the  bile-pigments,  while  the  iron 
seems  to  be  mostly  withheld  to  be  worked  over  into  new  hemo- 
globin. (See  "  Pigmentation, "  Chap,  xvi.)  Whenever  during 
disease  red  corpuscles  are  more  rapidly  injured  than  they  are 
under  normal  conditions,  these  processes  of  normal  hemolysis 
are  exaggerated  and  we  not  only  find  the  phagocytic  cells  of  the 
spleen  and  glands  packed  with  corpuscles,  but  endothelial  cells 
elsewhere,  and  also  leucocytes,  take  on  the  hemolytic  function. 
At  the  same  time  there  results  an  excessive  production  of  bile- 
pigment  from  the  destroyed  red  corpuscles,  which  has  an  etio- 
logical  relation  to  the  so-called  "  hemato-hepatogenous "  jaun- 
dice. If  hemolysis  is  very  excessive,  the  blood  pigment 
accumulates  in  other  organs  than  the  liver  and  spleen.  When 
at  one  time  over  one-sixtieth  part  of  the  hemoglobin  of  the 
blood  is  in  solution  in  the  plasma,  it  may  escape  in  the  urine, 
producing  hemoglobinuria. 

The  hemolysis  of  the  acute  febrile  diseases  is  readily  explained 
by  the  demonstrable  hemolytic  property  of  the  products  of  the 
organisms  that  cause  them,  such  as  streptocolysin,  staphylolysin, 
etc.  Perhaps  at  the  same  time  products  of  altered  metabolism 
may  also  play  a  part,  but  it  does  not  seem  probable  from  experi- 
mental results  that  the  thermic  condition  per  se  has  much  effect. 
In  malaria,  although  the  parasites  enter  and  destroy  the  cor- 
puscles in  which  they  live,  yet  this  alone  does  not  account  for 
all  the  blood  destruction  of  the  disease,  for  the  amount  of 
anemia  is  quite  without  relation  to  the  number  of  parasites  to 
be  found.  There  is  good  reason  to  believe  that  the  plasmodia 
produce  hemolytic  substances  that  are  discharged  into  the 
serum.1  In  the  primary  anemias  hemolysis  seems  to  be  the 
1  Regnault,  Rev.  d.  Med.,  1903  (23),  729. 


HEMOLYSIS  IN  DISEASE  201 

essential  process,  although  the  agents  involved  are  at  present 
unknown.  Absorption  of  hemolytic  products  of  intestinal 
putrefaction  or  infection  has  always  come  in  for  much  suspicion, 
without  ever  becoming  completely  established.  Here  also  the 
hemolysis  seems  to  take  place  in  the  endothelial  cells  rather 
than  in  the  vessels.  In  such  a  disease  as  pernicious  anemia 
there  is  much  reason  to  assume  that  defective  or  abnormal 
hematogenesis  is  an  important  factor.  Probably  the  anemia 
of  nephritis  is  the  result  of  hemolytic  action  of  the  retained 
products  of  metabolism,  in  which  connection  the  hemolytic 
properties  of  ammonium  compounds  may  be  recalled.  In  some 
diseases  associated  with  anemia  it  has  been  found  that  the 
blood-serum  of  the  patient  is  distinctly  isohemolytic,  although 
isoagglutination  seems  to  be  more  frequent.  The  fluids  that  can 
be  obtained  from  cancers  have  been  found  to  be  hemolytic,  while 
antihemolysin  has  been  found  in  ascitic  and  pleural  effusions. 

In  many  forms  of  poisoning  hemolysis  is  a  prominent  feature ; 
in  some  it  seems  to  be  the  chief  effect  of  the  poison,  e.  g.,  potas- 
sium chlorate  and  arseniuretted  hydrogen.  In  severe  extensive 
burns  there  may  occur  hemolysis,  and  hemoglobinuria  may  also 
result.  The  remarkable  "paroxysmal  hemoglobinuria"  is  at 
present  without  satisfactory  explanation  as  to  the  cause  of  the 
hemolysis  except  that  during  the  paroxysm  the  blood  is  hemo- 
lytic. The  hemoglobinemia  of  "  blackwater  fever  "  has  been 
the  cause  of  much  discussion  as  to  whether  the  malarial  parasite 
or  the  quinine  is  the  cause,  with  a  divided  opinion  resulting, 
although,  undoubtedly,  cases  do  occur  in  malaria  without  adminis- 
tration of  quinine.  After  removal  of  the  spleen  hemolysis  by 
the  hemolymph  glands  exceeds  that  of  the  primitive  spleen, 
causing  an  excessive  destruction  of  red  corpuscles  (Warthin l ). 
This  suggests  that  the  spleen  may  normally  dispose  of  some 
hemolytic  agent  which  acts  either  by  stimulating  phagocytosis 
or  by  so  altering  the  red  cells  that  they  are  particularly  suscep- 
tible to  phagocytosis. 

Pathological  Anatomy. — The  lesions  produced  in  the 
organs  of  animals  injected  with  hemolytic  agents  are  usually 
pronounced  and  quite  characteristic.  There  is  often  a  sub- 
cutaneous edema,  which  is  usually  blood-stained,  and  similar 
fluid  may  be  present  in  the  serous  cavities.  The  fat  is  yellowish, 
and  the  muscles  are  darker  in  color  than  is  normal;  The  spleen 
is  usually  much  swollen,  soft,  friable,  and  very  dark  in  color. 
The  liver  is  usually  swollen  and  mottled  with  red  areas  in  a 
yellow  background.  The  renal  cortex  is  dark  in  color,  even 
1  Jour.  Med.  Kesearch,  1902  (7),  435. 


202  HEMOLYSIS  AND  SERUM  CYTOTOXINS 

chocolate-colored,  and  the  pyramids  are  comparatively  light : 
hemoglobin  is  frequently  present  in  the  urine.  In  the  lungs 
are  often  found  hemorrhages  or  areas  resembling  small  infarcts. 
The  blood  may  be  thin  and  even  distinctly  transparent.  Micro- 
scopically the  red  corpuscles  are  found  in  all  conditions  of 
degeneration,  and  often  fused  together.  In  the  liver,  besides 
patches  of  congestion,  fatty  changes  are  present  if  the  animal 
lives  long  enough.  Large  phagocytic  cells  packed  with  red 
corpuscles  are  abundant  in  the  spleen  and  lymph-glands,  as 
well  as  diffuse  accumulations  of  the  blood-cells,  which  are  often 
fused ;  and  much  pigment  is  also  present,  both  free  and  in  the 
cells.  Pigment  also  accumulates  in  the  renal  epithelium,  which 
often  shows  much  disintegration  ;  congestion  is  prominent,  and 
hemorrhages  into  both  interstitial  tissue  and  glomerules  are 
frequent.  Some  of  the  lesions  are  due  to  the  hemolysis,  and 
some  to  the  associated  agglutination  of  corpuscles,  which  form 
hyaline  thrombi. 

Agglutination  of  corpuscles  in  the  vessels  during  life  is 
undoubtedly  of  much  pathologic  importance,  for  such  masses 
of  agglutinated  corpuscles  may  produce  extensive  formation  of 
capillary  thrombi  and  emboli,  from  which  serious  results  may 
be  produced.  (See  "Hyaline  Thrombi,"  Chap,  xi.)  Many 
bacteria  produce  substances  that  are  agglutinative  for  human 
red  corpuscles,  among  them  being  such  important  disease- 
producers  as  typhoid,  pyocyaneus,  and  staphylococcus.  Flexner l 
has  found  in  typhoid  fever  thrombi  that  seemed  to  be  composed 
of  agglutinated  red  corpuscles,  practically  free  from  fibrin  and 
leucocytes.  Probably  many  of  the  "  hyaline  thrombi  "  frequently 
found  in  infectious  diseases  are  really  composed  of  agglutinated, 
partly  hemolyzed  red  corpuscles.  Pearce2  has  found  that 
agglutinative  serum  when  injected  into  dogs  causes  wide- 
spread necrosis  in  the  liver,  which  is  followed  by  proliferation 
of  connective  tissue  and  the  production  of  changes  resembling 
cirrhosis. 

CYTOLYSIS  IN  GENERAL 

Not  the  same  degree  of  success  has  been  obtained  in  immunizing 
against  other  tissue  elements  as  with  the  erythrocytes.  Immune 
serum  can  readily  be  obtained  against  cells  that  can  be  secured 
quite  free  from  other  cells,  such  as  spermatozoa,  ciliated  epithe- 
lium, and  leucocytes,  but  even  then  the  immunity  is  not  specific. 

1  Univ.  of  Penn.  Med.  Bull.,  1902  (15),  324;  Amer.  Jour.  Med.  Sci.,  1903 
(126),  202. 

2  Jour.  Exp.  Med.,  1906  (8),  64;  Jour.  Med.  Kesearch,  1906  (14),  541. 


CYTOLYSIS  IN  GENERAL  203 

Much  less  is  it  specific  when  ground-up  organs  are  used  for 
immunizing,  as  is  the  case  in  the  experimental  production  of 
nephrolysins,  hepatolysins,  etc.,  for  at  the  same  time  antibodies 
are  secured  for  not  only  the  typical  parenchyma  cells,  but  also 
for  endothelium,  stroma  cells,  red  and  white  corpuscles,  and 
blood  plasma.  As  a  consequence,  the  early  expectations  that 
by  this  process  of  immunization  against  specific  cells  great 
progress  could  be  made  in  our  knowledge  of  physiology,  by 
selectively  throwing  .out  of  function  an  organ  through  the 
simple  process  of  injecting  an  antiserum,  have  been  disappointed. 
Equally  little  progress  has  been  made  in  the  treatment  of 
malignant  growths  by  the  same  method.  The  immune  serums 
usually  obtained  do,  to  a  certain  extent,  injure  the  specific  organ, 
but  they  also  usually  injure  other  organs  nearly  as  much  or 
perhaps  more ;  furthermore  they  generally  contain  hemolytic 
toxins,  even  if  the  tissues  used  in  immunizing  are  free  from 
blood,  and,  as  we  have  seen,  hemolytic  poisons  may  cause 
serious  tissue  destruction.1 

Beebe 2  has  introduced  a  method  of  immunization  that  may 
yield  better  results.  On  the  assumption  that  the  nucleoproteids 
are  the  most  characteristic  constituent  of  the  cells,  he  isolated 
them  from  different  organs,  and  claims  to  have  secured  serums 
by  immunizing  with  these  nucleoproteids  that  were  altogether 
specifically  toxic  for  the  type  of  cells  from  which  the  nucleo- 
proteids were  obtained ;  e.  g.y  immunizing  with  liver  nucleo- 
proteids yielded  serum  destroying  liver  cells  and  no  others. 

In  view  of  the  present  uncertain  state  of  the  subject,  and 
the  very  questionable  value  of  much  of  the  work  so  far  done, 
the  consideration  of  the  various  cytolysins  or  cytotoxins  may 
be  dismissed  by  briefly  referring  to  a  few  of  the  most  important 
results. 

I/eucocytolytic  Serum.3 — This  may  be  obtained  either 
by  immunizing  with  leucocytes  obtained  from  exudates  or  from 
the  blood,  or  by  using  emulsions  of  lymph-glands.  Specific  leu- 
cocytolytic  serum  agglutinates  leucocytes  and  produces  observ- 
able morphologic  changes,  in  the  way  of  solution  of  the  cyto- 
plasm and  cessation  of  ameboid  movements.  Of  the  leucocytes, 
the  large  granular  cells  seem  most  affected  and  the  lymphocytes 
least.  When  injected  into  the  peritoneal  cavity  such  serum 
causes  an  apparent  initial  leucopenia,  and  later  a  decided 

1  See  Sata,  Ziegler's  Beitr.,  1906  (39),  1. 

2  Jour.  Exp.  Med.,  1905  (7),  733. 

3  Literature,  see  Flexner,  Univ.  of  Penn.  Med.  Bull.,  1902  (15),  287;  Kicketts, 
Trans.  Chicago  Path.  Soc.,  1902  (5),  178 ;  Christian,  Deut.  Arch.  klin.  Med., 
1904  (80),  333. 


204  HEMOLYSIS  AND  SERUM  CYTOTOX1NS 

leucocytosis  in  the  peritoneal  fluid.  Corresponding  with  this,  if 
bacteria  are  injected  at  the  same  time  as  the  serum,  resistance 
is  found  decreased,  but  later  it  is  much  increased.  Such  serum 
also  contains  anticomplement,  according  to  Wassermann,  indi- 
cating that  the  injected  leucocytes  contain  complement.  Leuco- 
cytotoxin  obtained  by  immunizing  against  lymphatic  tissue  is 
very  thermolabile,  being  destroyed  by  55°  C.  for  thirty  minutes, 
and  the  serum  can  be  only  partially  reactivated  by  the  use  of 
fresh  serum. 

Endotheliolytic  Serum. — Every  attempt  at  immunizing 
an  animal  with  any  sort  of  fixed  tissue  must  of  necessity 
involve  the  injection  of  endothelial  cells  as  well  as  the  cells  speci- 
fic to  the  tissue  studied.  Therefore,  it  is  possible  that  cytotoxic 
serum  so  obtained  will  contain  endothelial  toxins  and  so  compli- 
cate any  results  of  intra  vitam  experiments.  There  is  every 
reason  to  believe  that  endotheliolytic  substances  are  produced 
in  this  way.  Ricketts  found  that  serum  of  animals  immunized 
against  lymph-glands  was  toxic  to  endothelial  cells,  which  was 
indicated  by  hemorrhages  at  the  point  of  injection,  and  marked 
desquamation  of  endothelium  when  the  injection  was  made  into 
a  serous  cavity.  In  snake- venom  poisoning  the  extensive  hemor- 
rhages are  also  due  to  an  endotheliolytic  principle,  called  by 
Flexner  hemorrhagin. 

I/ymphatolytic  Serum. — This  serum  has  been  studied 
by  Ricketts  and  by  Flexner,  who  immunized  animals  with 
lymph-glands.  As  might  be  expected  from  the  structure  of  the 
injected  glands,  the  resulting  serum  contained  endotheliotoxin, 
leucocytotoxin,  hemolysin,  hemagglutinin,  leucocyto-agglutinin, 
and  precipitins.  When  injected  into  animals,  this  serum  has  a 
marked  effect  upon  the  spleen  and  lymph-glands,  producing 
great  enlargement  and  congestion  of  these  structures.  The  bone- 
marrow  is  also  somewhat  affected,  and  when  marrow  is  used  in 
immunizing,  the  mydotoxic  serum  produces  marked  proliferative 
changes  in  the  lymph-glands  as  well  as  in  the  marrow. 

Nephrolytic  Serum. — It  has  been  claimed  that  if  a 
kidney  is  destroyed  by  ligating  its  vessels  or  ureter,  the  remain- 
ing kidney  develops  serious  degenerative  changes,  which  are  not 
present  if  one  kidney  is  entirely  removed.  This  has  been 
attributed  to  the  development  of  nephrotoxic  substances  pro- 
duced in  reaction  to  the  absorption  of  the  injured  renal  tissue 
that  has  been  left  in  the  body.  Other  methods  of  renal  injury 
have  been  thought  to  produce  similar  effects,  and  serum  of  ani- 
mals with  kidney  disease  was  said  to  injure  the  kidneys  of 
normal  animals.  Upon  this  basis  it  has  been  thought  possible 


CYTO LYSIS  IN  GENERAL  205 

to  explain  the  progressive  nature  of  the  chronic  nephritides  as 
the  result  of  nephrotoxins  produced  through  the  absorption  of 
the  injured  cells,  which  nephrotoxins  injure  still  other  renal  cells. 
Such  a  process,  however,  involves  the  production  of  cell  toxins 
in  an  animal  that  are  toxic  for  its  own  cells,  that  is,  autocyto- 
toxins ;  and  as  it  has  so  far  been  practically  impossible  to 
produce  autolysins  of  other  sorts,  it  is  not  altogether  probable 
that  the  kidney  is  an  exception.  Furthermore,  Pearce1  was 
unable  to  produce  isonephrotoxins,  and  could  not  corroborate 
the  statements  as  to  the  changes  said  to  have  been  found  in  the 
remaining  kidney  after  ligating  the  vessels  of  its  mate.  He  did 
obtain  an  active  heteronephrolysin,  but  also  found  that  immuni- 
zation with  liver  produced  nearly  as  actively  nephrolytic  serum 
as  did  immunization  with  kidney. 

Neurolytic  Serum. — Even  as  highly  specialized  cells  as 
those  of  the  nervous  tissue  seem  to  produce  a  reaction  with  the 
formation  of  immune  bodies.  Perhaps  the  most  positive  results 
are  those  of  Ricketts  and  Rothstein,2  who  found  that  serum  of 
rabbits  immunized  against  the  brains  or  cords  of  guinea-pigs 
was  highly  toxic  when  injected  into  the  vessels  of  guinea-pigs, 
causing  death  with  various  symptoms  only  explainable  on  the 
assumption  of  nervous  lesions.  Microcospically,  the  ganglion- 
cells  showed  marked  changes  in  those  animals  that  survived 
the  injection  long  enough.  All  the  results  so  far  obtained  have 
been  with  heterogeneous  serum.  Venoms,  particularly  that  of 
cobra,  possess  strong  neurolytic  substances  that  are  the  chief 
toxic  agents  in  most  of  the  venoms  (rattlesnake  venom  excepted). 

Thyrolytic  Serum. — There  are  but  few  reports  on  this 
serum,  but  that  of  Portis  3  indicates  that  after  removal  of  all 
hemolysis  as  a  factor  there  do  occur  changes,  in  the  nature  of 
excessive  absorption  of  colloid,  and  proliferation  after  the 
order  of  that  seen  in  thyroid  regeneration.  However,  the 
clinical  picture  of  thyroidectomy  was  not  produced  in  any  case, 
and  the  anatomic  changes  were  not  great.  By  immunizing 
against  nucleoproteids  derived  from  thyroid  tissue,  Beebe 4  has 
secured  an  antiserum  which  seems  to  have  some  effect  upon 
diseased  thyroids  (exophthalmic  goiter).  MacCallum5  could 
not  get  a  specific  serum  for  parathyroid  tissue. 

Numerous  reports  may  be  found  indicating  attempts,  with 
varying  success,  to  obtain  serums  toxic  for  other  tissues.  Among 

1  Univ.  of  Penn.  Med.  Bull.,  1903  (16),  217. 

2  Trans.  Chicago  Path.  Soc.,  1903  (5),  207. 

3  Jour.  Infectious  Diseases,  1904  (1),  127. 

4  Jour.  Araer.  Med.  Assoc.,  1906  (46),  484.       5  Med.  News,  1903  (83),  820. 


206  HEMOLYSIS  AND  SERUM  CYTOTOXINS 

them  may  be  mentioned  epitheliolysin  (for  ciliated  epithelium), 
spermatotoxin,  hepatolysin,  eardiolysin,  splenolysin,  and  syncy- 
tiolysin.  Attempts  at  the  production  of  immune  serum  with 
adrenal  by  Abbott l  resulted  only  in  a  serum  with  great  hemo- 
lytic  power,  but  with  no  particular  effect  on  the  adrenal.  In 
general  it  can  be  said  that  it  has  not  been  found  possible  in  this 
way  to  throw  out  of  function  one  particular  organ,  with  or  with- 
out involvement  of  other  structures.  The  most  suggestive 
results  have  been  obtained  by  Beebe,2  who  has  used  nucleo- 
proteids  of  specific  organs  in  immunizing. 

The  principles  involved  in  all  these  experiments  are  the 
same,  and  the  results  are  in  no  instance  altogether  satisfactory ; 
therefore  no  further  consideration  of  these  special  cytotoxic 
serums  will  be  made  here,  the  reader  being  referred  to  a  com- 
plete resume"  and  bibliography  of  the  subject  by  Sachs3  for 
details. 


1  Jour.  Med.  Eesearch,  1903  (9),  329. 

2  Jour.  Exp.  Med.,  1905  (7),  733. 


3  Biochemisches  Centralblatt,  1903  (1),  573  ;  et  seq. ;  also  see  Sata,  Ziegler's 
Beitr.,  1906  (39),  1. 


CHAPTER    X 
INFLAMMATION 

ALTHOUGH  morphological  alterations  are  prominent  features 
of  the  reaction  of  the  tissues  to  local  injury  and  infection,  yet 
at  the  bottom  the  processes  of  inflammation  are  brought  about 
by  and  result  in  chemical  alterations.  The  causes  of  inflamma- 
tion are  in  nearly  all  cases  chemically  active  substances,  but  for 
the  most  part  their  nature  is  too  little  known  to  permit  of 
speculation  as  to  what  chemical  characteristic  or  characteristics 
a  substance  must  possess  to  exhibit  the  power  of  causing  an 
inflammatory  reaction.  Even  in  the  case  of  inflammation  due 
to  mechanical,  thermal,  and  electrical  injuries,  it  seems  probable 
that  most  of  the  features  of  the  inflammatory  reaction  are 
brought  about  by  the  action  of  chemical  substances  produced 
by  alterations  in  the  tissue  constituents  at  the  point  of  injury. 

The  essential  features  of  inflammation,  namely,  local  hyper- 
emia  and  related  vascular  disturbances,  exudation  of  plasma, 
migration  of  leucocytes  and  their  phagocytic  action,  all  may  be 
caused  by  the  action  of  chemical  substances  upon  the  vessels  and 
leucocytes.  Active  hyperemia  in  the  case  of  inflammation  is  due 
to  stimulation  of  the  vasodilator  nerves  or  paralysis  of  the  vaso- 
constrictors, or  direct  paralysis  of  the  muscular  fibers  of  the 
arterioles ;  these  may  result  from  mechanical,  thermal,  or 
electrical  stimuli,  but  in  local  infection  the  cause  is  usually 
chemical  products  of  bacterial  growth  or  of  tissue  disintegra- 
tion. The  escape  of  blood  plasma  (inflammatory  edema)  appears 
to  depend  upon  a  number  of  factors  (discussed  more  fully  under 
"Edema/7  Chap,  xii)  of  which  the  most  important  seem  to 
be :  (1)  injury  to  the  capillary  walls,  produced  largely  by  the 
chemical  causes  or  products  of  the  inflammation  ;  (2)  increased 
osmotic  pressure  in  the  tissues,  due  to  increased  or  abnormal 
formation  of  crystalloidal  substances  with  high  osmotic  pressure 
from  large  molecular  compounds,  many  of  which  are  colloids 
(proteids)  without  appreciable  osmotic  pressure.  By  far  the 
most  characteristic  feature  of  inflammation,  however,  is  the 
behavior  of  the  leucocytes — their  increase  in  number  in  the  blood, 
their  migration  from  the  vessels  and  accumulation  about  the 
point  of  injury,  and  their  engulfing  and  destroying  various 

207 


208  INFLAMMATION 

solid  particles,  such  as  bacteria  and  degenerating  tissue  elements. 
These  processes,  which  seem  to  indicate  something  approaching 
independent  volition  on  the  part  of  the  leucocytes,  may,  how- 
ever, be  well  explained  by  application  of  known  laws  of  chemis- 
try and  physics,  without  passing  into  the  realms  of  the  meta- 
physical. This  will  be  attempted  under  the  heading  of: 

AMEBOID  MOTION  AND  PHAGOCYTOSIS 

The  accumulation  of  leucocytes  at  a  given  point  in  the  body 
indicates  that  some  means  of  communication  must  exist  between 
this  point  and  the  leucocytes  in  the  circulating  blood.  No  direct 
communication  by  the  nervous  system  or  other  structural  meth- 
od existing,  the  only  possible  explanation  is  that  the  communi- 
cation is  through  the  fluids  of  the  body,  and  depends  upon 
changes  in  their  chemical  composition  or  physical  condition. 
As  the  latter  generally  depends  upon  the  former,  the  communi- 
cation is  considered  to  be  accomplished  by  chemical  agencies, 
and  called  chemotaxis. 

CHEMOTAXIS 

Changes  in  the  chemical  composition  of  a  fluid  have  been 
shown  frequently  to  affect  the  motion  of  living  organisms  sus- 
pended in  it.  One  of  the  earliest  observations  wras  that  of 
Engelmann,1  who  noticed  that  Bacterium  termo  suspended  in 
water  tended  to  accumulate  about  a  bubble  of  oxygen  in  the 
water.  Pfeifer2  discovered  that  the  spermatozoids  of  certain 
ferns  were  attracted  powerfully  by  very  dilute  solutions  of  malic 
acid,  which  is  contained  in  the  female  sperm  cell,  indicating  that 
the  migration  of  the  sperm  cells  in  the  proper  direction  depends 
on  a  chemical  communication,  and  he  proposed  the  term  chemo- 
taxis for  this  phenomenon.  Strong  solutions  of  malic  acid,  on 
the  other  hand,  repelled  spermatozoids.  Cane-sugar  was  found 
to  attract  the  spermatozoids  of  a  certain  foliaceous  moss.  In 
the  case  of  the  malic  acid,  it  seems  to  be  the  anion  that  produces 
the  effect,  since  salts  of  malic  acid  have  exactly  the  same 
property. 

StahPs3  experiment  with  a  large  jelly-like  plasmodium  (Aethal- 
ium  septicum)  growing  on  bark  in  wet  places,  has  become  class- 
ical. He  found  that  if  the  plasmodium  was  placed  on  a  moist 
surface,  and  near  by  was  placed  a  drop  of  an  infusion  of  oak 
bark,  the  organism  moved  by  the  process  of  protoplasmic  stream- 

1  Botanische  Zeitung,  1881  (39),  441. 

2  Untersuch.  aus  dem  Bot.  Institut  in  Tiibingen,  1881-1888,  Bd.  1  und  2. 

3  Botanische  Zeitung,  1884  (42),  145  and  161. 


CHEMO  TAXIS  209 

ing  toward  and  into  the  infusion.  If  a  piece  of  oak  bark  was 
placed  in  the  water,  plasmodial  arms  were  stretched  out  to  it 
and  the  piece  of  bark  was  soon  completely  surrounded  by  the 
organism.  These  movements  were  found  to  occur  in  any  direc- 
tion, even  exactly  against  the  force  of  gravity.  Other  sub- 
stances, as  acids  or  strong  solutions  of  salt  or  sugar,  were  found 
to  cause  the  plasmodium  to  move  away  from  them,  although 
when  sufficiently  dilute  they  exerted  an  attraction.  A  plasmo- 
dium might,  however,  move  into  a  strong  sugar  solution  if  kept 
with  a  scanty  supply  of  moisture  for  some  time,  and  after  it 
had  lived  in  such  a  strong  solution  (2  per  cent.)  for  some  time, 
a  weaker  solution  or  pure  water  .was  as  injurious  as  the  con- 
centrated sugar  solution  previously  had  been. 

Temperature  was  also  found  to  exert  a  marked  thermotactic 
effect.  If  a  plasmodium  was  placed  on  a  filter-paper,  one  end 
of  which  was  in  water  at  7°,  and  the  other  in  water  at  30°,  it 
would  move  toward  the  warmer  end. 

The  Theory  of  Tropisms. — Ciliated  protozoa,  which  can 
move  about  freely  in  water,  show  very  distinct  reactions  to 
stimuli  of  all  sorts.  The  first  step  in  their  change  of  direction 
of  movement  is  considered  by  many  observers l  to  be  an  orienta- 
tion of  the  organism  until  it  is  headed  in  the  axis  along  which 
it  is  to  move.  This  is  ascribed  by  Loeb 2  to  the  existence  of  a 
certain  degree  of  equality  of  irritability  of  symmetrical  parts  of 
the  body.  The  stimulant,  whether  it  be  rays  of  light,  or  diffus- 
ing chemicals,  or  heat-waves,  moves  along  definite  lines,  and 
the  organism  receives  at  first  unequal  stimuli  on  symmetrical 
parts  of  the  body,  unless  the  axis  of  the  organism  is  parallel  to 
the  lines  of  motion  of  the  stimulant.  As  long  as  the  stimulant 
acts  on  symmetrical  parts  of  the  body  unequally,  these  parts  will 
react  unequally  until  at  length  the  body  is  swung  into  a  position 
where  the  stimulation  is  equal,  when  it  will  stay  in  this  position 
and  move  along  a  line  parallel  to  the  line  taken  by  the  stimu- 
lant. Not  only  protozoa,  but  much  higher  forms,  including 
some  vertebrates,  are  believed  to  react  in  this  way  to  stimuli — 
e.  g.j  the  maintenance  by  fish  of  a  position  heading  up  stream. 
The  above  constitutes  the  so-called  "  theory  of  tropisms"  and  we 
have  such  reactions  to  stimuli  of  all  sorts,  not  only  chemotropism 
and  thermotropism,  but  also  heliotropism  (reaction  to  light); 
geotropism  (to  gravity),  electropism  (to  electricity),  thigmotropism 
(reaction  to  contact),  etc. 

1  Jennings  does  not  accept  this  view,  but  attributes  the  results  to  processes  of 
"  trial  and  error." 

*  Comparative  Physiology  of  the  Brain,  New  York,  1900,  p.  7. 

14 


210  INFLAMMATION 

The  work  done  upon  tropisms  applies  particularly  to  ciliated, 
freely  motile  organisms,  and  interests  us  less  in  connection  with 
leucocytes  than  do  the  observations  on  such  forms  as  Amoeba.1 
In  passing  may  be  mentioned  the  thigmotaxis  or  thigmotropism 
(reaction  to  mechanical  stimuli)  shown  by  spermatozoa,  which 
explains  their  apparently  difficult  feat  of  advancing  in  opposi- 
tion to  the  cilia  of  the  epithelium  lining  the  female  generative 
tract.  It  may  also  be  noted  that  the  nature  of  reactions  of 
organisms  to  various  stimuli  is  not  constant  for  even  the  same 
organism.  Copepods.  (minute  Crustacea)  may  be  negatively 
heliotropic  in  the  day  and  go  away  from  the  bright  surface  of 
the  water,  whereas  at  night  the  same  animals  are  positively 
heliotropic  and  swarm  to  the  surface,  illuminated  brightly  by  a 
lantern.  Variations  in  heliotropism  may,  in  some  cases,  be 
explained  as  due  to  chemical  changes  that  occur  in  the  organism, 
which  explanation  is  made  more  probable  by  J.  Loeb's  experi- 
ments, which  show  that  change  in  composition  in  the  fluid  in 
which  animals  are  suspended  may  cause  a  complete  reversal  in 
their  reaction  to  a  constant  stimulus.2  Motile  bacteria  seem  to 
behave  much  like  ciliated  protozoa  in  their  reaction  to  stimuli. 

CHEMOTAXIS  OF  LEUCOCYTES 

That  leucocytes  come  to  the  site  of  an  infection  because  of 
chemical  substances  produced  by  bacteria  at  this  point,  that  is 
to  say,  through  chemotaxis,  was  first  clearly  pointed  out  by 
Leber3  in  1879,  who  likened  the  attraction  of  such  substances 
for  leucocytes  to  the  effect  of  malic  acid  upon  spermatozoids  as 
shown  by  Pfeffer.  He  found  that  in  keratitis  leucocytes 
invaded  the  avascular  cornea  from  the  distant  vessels,  not  in  an 
irregular  manner,  but  all  moved  directly  toward  the  point  of 
infection,  where  they  collected.  As  dead  cultures  of  staphy- 
lococci  produced  a  similar,  although  less  marked,  accumulation 
of  leucocytes,  he  sought  the  chemotactic  substance  in  their 
bodies,  and  isolated  a  crystalline,  heat-resisting  substance, 
phlogosin,  which  attracted  leucocytes  in  animal  tissues.  He 
also  observed  that  capillary  tubes  filled  with  phlogosin  or  with 
staphylococci  were  soon  invaded  by  masses  of  leucocytes. 

Since  Leber's  experiments,  many  other  investigations  have 

1  For  full  details  see  Jennings   (Publication  No.  16,  Carnegie  Institute, 
Washington,  1904) ;  also  J.  Loeb,  "Studies  in  General  Physiology." 

2  Barratt  (Zeit  f.  allg.  Physiol.,  1904  (4),  87),  however,  was  unable  to  dem- 
onstrate that  quantities  of  acids  and  alkalies  just  sufficient  to  kill  paramoecium 
produced  any  change  in  the  reaction  of  their  protoplasm  great  enough  to  be 
detected  by  stains  or  by  indicators,  although  it  is  well  known  that  much  smaller 
quantities  exert  marked  chemotactic  effects. 

3  Fortschritte  der  Med.,  1888  (6),  460. 


CHEMOTAXIS  211 

been  made  showing  that  chemical  substances  of  many  different 
origins  other  than  bacterial  exert  a  chemotactic  influence  on 
leucocytes.  Some  substances  are  indifferent  in  effect,  most  are 
positive,  while  some  are  believed  to  repel  leucocytes ;  i.  e.y  are 
negatively  chemotactic. 

Negative  Chemotaxis. — Probably  the  substances  that  repel 
leucocytes  are  few  in  number ;  Kanthack,  indeed,  doubted  the 
existence  of  really  negative  chemotactic  action  upon  leucocytes. 
Verigo l  also  considers  that  as  yet  no  actual  negative  chemotaxis 
has  been  satisfactorily  demonstrated  ;  but,  by  analogy  with  the 
effects  of  chemicals  on  ameba,  ciliata,  and  plasmodial  forms, 
which  all  show  a  decided  negative  chemotaxis  under  certain 
influences,  it  would  seem  most  probable  that  leucocytes  also 
should  be  repelled  as  well  as  attracted  by  chemicals.2 

Non-bacterial  Chemotactic  Substances. — One  of 
the  earliest  significant  studies  of  the  effects  of  non-bacterial 
substances  upon  chemotaxis  was  made  by  Massart  and  Bordet,3 
who  showed  that  products  of  the  disintegration  of  leucocytes 
and  other  cells  had  a  strong  positive  chemotactic  influence. 
They  also  corroborated  the  statement  of  Vaillard  and  Vincent 
that  lactic  acid  is  an  actively  repellant  substance,  for  they 
found  that  tubes  containing  a  pyocyaneus  culture,  which  ordi- 
narily become  filled  with  leucocytes  rapidly,  did  not  become 
invaded  at  all  if  lactic  acid  was  also  added  in  a  strength  of 
1  :  500,  although  leucocytes  did  enter  when  the  dilution  was 
1  : 1000. 

Gabritchevsky 4  studied  the  chemical  influence  of  a  large 
number  of  substances  on  leucocytes  and  divided  them  into 
three  groups  :  I.  Substances  exerting  "  negative  chemotaxis/' 
including  those  that  attracted  only  a  few  leucocytes.5  II.  Sub- 
stances with  "  indifferent  chemotaxis,"  which  attracted  moderate 
numbers  of  leucocytes.  III.  Substances  with  positive  chemo- 
taxis. If  we  correct  the  groupings  made  by  Gabritchevsky 
we  have  the  following  classification  : 

1  Arch.  d.  Med.  exper.,  1901  (13),  585. 

^Salomonsen's  observation  (Festskrift  ved  indyielsen  af  Statens  Serum 
Institut,  Kopenhagen,  1902,  Art.  XII),  that  ciliated  infusoria  when  killed  show 
a  strong  negative  effect  on  other  ciliates,  is  of  much  interest,  particularly  as  it 
seems  to  be  the  opposite  of  the  positively  chemotactic  effect  of  dead  upon 
living  leucocytes.  The  negative  reaction  of  different  ciliata  was  specific  for 
their  own  kind  quantitatively,  but  not  qualitatively. 

3  Ann.  d.  T  Inst.  Pasteur,  1891  (5),  417. 

4  Ann.  d.  1'  Inst.  Pasteur,  1890  (4),  346. 

5  Evidently  these  substances  were  not  all  negatively  chemotactic,  but  were 
relatively  slightly  chemotactic  or  indifferent ;  yet  in  the  literature  generally 
these  experiments  have  been  cited  as  indicating  a  negative  chemotactic  influence 
of  the  substances  studied. 


212  INFLAMMATION 

I.     Substances  negatively  chemotactic  or  indifferent : 
(a)  Concentrated  solutions  of  sodium  and  potassium  salts; 
(6)  Lactic   acid    in   all  concentrations ;    (c)  quinine 
(0.5  per  cent.)  ;  (d)  alcohol  (10  per  cent.) ;  (e)  chloro- 
form in  watery  solution  ;    (/)  jequirity  (2  per  cent., 
passed    through   Chamberlaud    filter) ;    (</)  glycerine 
(10  per  cent,  to  1  per  cent);  (A)  bile;  (t)  B.  cholerce 
yallinarium. 
II.     Substances  with  feeble  chemotaxis  : 

(a)  Distilled  water  ;  (6)  dilute  solutions  of  sodium  and 
potassium  salts  (1-0.1  per  cent.)  ;  (c)  phenol ;  (d) 
antipyrin  ;  (e)  phloridzin  ;  (/)  papayotin  (in  frog)  ; 
( 9)  glycogen  ;  (h)  peptone ;  (i)  bouillon  ;  (j)  blood 
and  aqueous  humor  ;  (k)  carmine. 
III.  Substances  with  strong  positive  chemotaxis  : 

(a)  Papayotin  (in  rabbits)  ;  (6)  sterilized  living  cultures 

of  bacteria,  whether  pathogenic  or  non-pathogenic. 
These  results  can  only  be  considered  as  suggestive  and  not 
as  accurate  findings,  in  view  of  other  contradictory  results. 
Buchner  *  obtained  from  the  pneumobacillus  of  Friedlander,  a 
proteid  which  exerted  a  strong  chemotactic  influence,  thus 
showing  the  chemical  nature  of  the  attraction  of  leucocytes  by 
bacteria,  and  he  isolated  other  similar  proteids  from  other  bac- 
teria. He  also  obtained  a  "  glutin-casein  "  from  grain  which 
was  related  chemically  to  the  bacterial  proteids,  and  which  was 
equally  chemotactic.  The  metabolic  products  of  bacteria,  how- 
ever, he  found  to  be  negatively  chemotactic.  Alkali  albuminate 
and  hemi-albumose  were  strongly  positive,  but  peptone  was  not. 
Glycocoll,  and  leucin  were  found  to  be  chemotactic,  but  urea, 
ammonium  urate,  skatol,  tyrosin,  and  trimethylamin  were  not. 
It  was  also  observed  that  if  the  positively  chemotactic  substances 
were  injected  subcutaneously,  they  produced  general  as  well  as 
local  leucocytosis. 

v.  Sicherer2  found  that  chemotaxis  of  leucocytes  may  be  ob- 
served outside  the  body.  If  a  tube  containing  positively  chemo- 
tactic substances  (dead  beer-yeast  cells  and  dead  staphylococci 
were  the  strongest)  is  placed  with  one  end  in  a  leucocyte-con- 
taining exudate,  the  leucocytes  pass  up  into  it  against  gravity. 

Bloch3  demonstrated  that  carbol-glycerine  extracts  made 
from  each  of  the  different  viscera  and  tissues  exerted  a  positive 
chemotaxis,  discrediting  the  statements  of  Goldscheider  and 

1  Berl.  klin.  Wochenschr.,  1890  (27),  1084. 

2  Cent.  f.  Bakt.,1899  (26),  360. 

3  Cent.  f.  allg.  Path.,  1896  (7),  785. 


CHEMOTAXIS  213 

Jacob  that  only  extracts  of  hematogenetic  tissues  showed  positive 
chemotaxis.  Egg-albumen,  gelatine,  albumen-peptone,  and 
alkali  albuminate  were  also  positive,  carbohydrates  feebly  so, 
and  fat  not  at  all.  Metallic  copper,  iron,  mercury,  and  their 
salts  have  also  been  found  to  be  chemotactic  substances,  but  it 
is  very  probable  that  they  act  in  part  through  destroying  the 
tissues  in  their  vicinity,  which  give  rise  to  decomposition-products 
having  a  positive  eifect.  Adler,1  however,  found  that  bichloride 
of  mercury  as  dilute  as  1  : 3000  caused  more  leucocytic  invasion 
of  a  piece  of  saturated  elder  pith  than  did  even  cultures  of 
pyogenic  bacteria.2 

Metchnikoif  observed  that  leucocytes  might,  after  a  time,  be 
attracted  toward  substances  that  at  first  seemed  to  repel  them. 
If  the  blood  is  full  of  toxins,  the  subcutaneous  introduction  of 
bacteria  does  not  lead  to  a  local  accumulation  of  leucocytes,  pre- 
sumably because  the  difference  in  chemotaxis  between  the  blood 
and  the  tissue  fluids  is  not  great  enough  to  cause  emigration ; 
in  this  connection  should  be  mentioned  Pfeffer's  observation 
that  B.  termo  in  a  peptone  solution  will  not  migrate  toward 
another  stronger  peptone  solution  unless  the  latter  is  at  least 
five  times  as  strong  as  the  former. 

Relation  of  Cell  Types  to  Migration.— Of  the  leuco- 
cytes, the  most  actively  affected  by  chemotaxis  is  the  polymor- 
phonuclear  variety,  but  not  all  substances  affect  each  variety 
of  leucocyte  in  the  same  way  ;  for  example,  infections  with  most 
animal  parasites  result  in  both  local  and  general  increase  in  the 
eosinophilous  forms,  and  similar  effects  have  been  obtained  by 
the  injection  of  extracts  of  animal  parasites.  Lymphocytes  are 
much  less  active,  presumably  because  they  contain  less  of  the 
mobile  cytoplasm  and  consist  chiefly  of  the  structurally  fixed 
nuclear  substance.  Undoubtedly  many  of  the  cells  in  so-called 
lymphocytic  accumulations  seen  in  certain  conditions,  such  as 
tuberculosis,  are  not  lymphocytes  from  the  blood,  but  are  newly 
divided  cells  of  the  tissue.3  The  experimental  evidence  concern- 
ing lymphocytic  emigration  is  very  contradictory.  Fauconnet 4 
has  found  that  tuberculin  injections  cause  in  man  general  in- 
crease in  leucocytes,  but  only  of  the  polymorphonuclear  form. 
Long-continued  intoxication  of  animals,  however,  may  result  in 
lymphocytic  increase,  but  local  introduction  of  the  toxin  leads  to 
accumulation  of  polymorphonuclear  cells  and  not  lymphocytes. 

1  Festschr.  for  A.  Jacobi,  1900,  New  York. 

2  Concerning   the   effects   of   iodin   and  iodides  upon  the   leucocytes,  see 
Heinz,  Virchow's  Arch.,  1899  (155),  44. 

3  See  re'sume'  by  Pappenheim,  Folia  Hematol.,  1905  (2),  815. 

4  Deut.  Arch.  klin.  Med.,  1904  (82),  167. 


214  INFLAMMATION 

Particularly  significant  is  the  experiment  of  Reckzeh,1  who 
found  that  in  lymphatic  leukemia,  with  the  lymphocytes  greatly 
exceeding  the  polymorphonuclear  forms  in  the  blood,  the  pus 
from  an  acne  pustule  or  from  cantharides  blisters  contains  prac- 
tically no  lymphocytes,  but  is  composed  of  the  usual  polynuclear 
forms.  Wolff,2  however,  claims  that  tetanus  and  diphtheria 
toxin  produce  lymphocytosis  in  experimental  animals.  Wlassow 
and  Sepp 3  state  that  lymphocytes  are  not  capable  of  ameboid 
movement  or  phagocytosis  in  the  body,  although  after  heating 
to  44°  they  may  become  motile  for  a  short  time. 

Experiments  on  the  nature  of  the  leucocytes  attracted  by  dif- 
ferent chemotactic  agents  have  been  made  by  Borissow4  and 
Adler.5  Both  agree  in  stating  that  none  of  the  substances  tested 
shows  any  special  affinity  for  any  single  type  of  leucocytes. 
Usually  the  polymorphonuclear  cells  in  exudates  far  exceeded 
their  proportion  in  the  circulating  blood.  Tissue  cells  were 
found  by  Adler  to  migrate  far  into  blocks  of  elder  pith,  appar- 
ently rather  later  than  the  leucocytes.  As  they  showed  changes 
of  form  indicating  ameboid  motions  he  considers  their  migra- 
tion to  be  an  active  process.  The  existence  of  the  polymor- 
phonuclear forms  in  the  pith  seems  to  be  very  transient. 

The  position  taken  by  the  young  blood-vessels  and  cells  in 
granulation  tissue,  at  right  angles  to  the  surface,  possibly  also 
depends  on  chemotaxis  determining  the  direction  in  which  the 
new  cells  shall  proliferate. 

Thermotaxis  of  I/eucocytes. — Heat  seems  to  affect  leu- 
cocytes much  as  it  does  ameba,  moderate  temperatures  being 
positively  thermotactic.  Mendelssohn 6  states  that  the  thermo- 
taxis  is  most  pronounced  at  a  temperature  of  36°-39°  C. 
(97°-102°  F.),  but  is  still  marked  as  low  as  20°  C.  Tem- 
peratures higher  than  39°  C.  (102°  F.)  do  not  seem  to  attract 
them.  Wlassow  and  Sepp 7  state  that  motility  of  leucocytes  is 
increased  by  warming  to  40°  C.,  and  that  temperature  of  42° 
-46°  C.  causes  the  movements  to  become  very  irregular,  with 
feeble  power  of  contraction.  Lymphocytes  are  not  motile  at 
ordinary  temperature,  but  at  44°  they  begin  to  move,  and  once 
motile,  they  continue  their  motion  when  cooled  as  low  as  35°  ; 
this  motility  is  considered  to  be  entirely  abnormal  and  only  the 
result  of  degenerative  changes. 

Temperature  probably  plays  but  a  minor  part  in  attracting 

1  Zeit.  f.  klin.  Med.,  1903  (50),  51.          2  Berl.  klin.  Woch.,  1904  (41),  1273. 
3  Virchow's  Arch.,  1904  (176),  185.        4  Ziegler's  Beitrage,  1894  (16),  432. 

5  Festschrift  f.  A.  Jacobi,  New  York,  1900. 

6  Koussky  Vratch,  1903.  7  Virchow's  Archiv,  1904  (176),  185. 


PHAGOCYTOSIS  215 

leucocytes  in  pathological  processes,  however.  The  local  heat 
of  au  inflamed  area  is  due  chiefly  to  the  accumulation  of  blood 
in  the  part,  and  would  not  influence  the  leucocytes  to  migrate 
from  the  still  warmer  blood  into  the  tissues.  By  increasing 
motility,  however,  the  temperature  of  fever  may  favor  migration 
and  phagocytosis,  and  local  application  of  heat  to  inflamed  areas 
may  induce  local  leucocytic  accumulation.  In  burns  the  dura- 
tion of  the  period  of  excessive  temperature  is  usually  too  brief 
to  account  for  the  attraction  of  leucocytes  that  results ;  this 
accumulation  is  undoubtedly  due  to  the  products  of  the  result- 
ing cell  degenerations. 

The  influence  of  light,  mechanical  stimulation,  and  gravity 
upon  leucocytes  seems  not  to  have  been  studied.  The  phagocy- 
tosis of  insoluble  non-nutritive  particles  has  been  ascribed  to 
taetile  stimulation,  but  the  details  of  the  operation  of  such  stim- 
uli are  unknown,  and  the  entire  question  of  tactile  stimulation 
is  unsettled.  In  experiments  with  elder  pith  it  has  been  ob- 
served that  leucocytes  penetrate  to  the  center,  even  when  the 
pith  contains  only  physiological  salt  solution.  As  Adler  re- 
marks, it  is  difficult  to  explain  such  migration  as  due  to  tactile 
stimuli ;  but,  on  the  other  hand,  no  other  explanation  has  been 
offered. 

PHAGOCYTOSIS 

The  engulfing  of  bacteria,  cells,  tissue  products,  etc.,  by  leu- 
cocytes seems  to  be  but  an  extension  of  the  phenomenon  of 
chemotaxis.  When  the  substance  toward  which  the  leucocyte 
is  drawn  is  small  enough,  the  leucocyte  simply  continues  its 
motion  until  it  has  flowed  entirely  about  the  particle.  Later 
the  particle  becomes,  as  a  rule,  more  or  less  altered  within  the 
cell,  unless  it  is  a  perfectly  insoluble  substance,  such  as  a  bit 
of  coal-dust.  This  action  upon  the  engulfed  object  is  un- 
doubtedly due  to  the  action  of  intracellular  enzymes.1  Protozoa 
take  their  food  into  a  specialized  digesting  vacuole  which  has 
been  shown  by  Le  Dantec 2  (in  Stentor,  Paramcecium,  and  some 
other  varieties)  to  contain  a  strongly  acid  fluid.  Miss  Green- 
wood 3  has  also  demonstrated  acid  in  several  forms  of  protozoa, 
which  is  formed  under  stimulation  of  injected  particles,  whether 
nutritious  or  not.  Mouton 4  has  been  able  to  extract  from  the 
bodies  of  protozoa  (rhizopods)  a  feebly  proteolytic  enzyme. 

1  See  Opie,  Jour.  Exp.  Med.,  1906  (8),  410. 

2  Ann.  d.  1'  Inst.  Pasteur,  1890  (4),  776. 

3  Jour,  of  Physiol.,  1894  (16),  441. 

4  C.  K.  Acad/des  Sciences,  1901  (133),  244. 


216  INFLAMMATION 

This  "  amibodiastase, "  as  he  calls  it,  is  active  in  alkaline,  and 
faintly  acid  media,  and  digests  colon  bacilli  that  have  been 
killed  by  heat,  but  not  living  bacilli.  This  last  fact  is  highly 
suggestive  in  connection  with  the  important  question  of  whether 
leucocytes  engulf  and  destroy  virulent  bacteria  or  only  those 
that  have  been  previously  injured  by  the  tissue  fluid.  It  was 
impossible  to  secure  either  invertase  or  lipase  in  extracts  of 
protozoa.  Whether  bacteria  are  digested  in  leucocytes  by  the 
same  enzymes  that  digest  the  leucocytes  themselves  after  they 
are  killed  (i.  e.,  the  autolytic  ferments),  or  by  some  specialized 
enzyme,  is  not  known.  Metchnikoif,  however,  has  noted  the 
localized  production  of  acid  in  the  cytoplasm  of  leucocytes  of 
the  larva  of  Triton  toeniatus.  The  eventual  excretion  of  the 
remains  of  the  bacteria  or  other  foreign  bodies  by  the  phagocytes 
is  ascribed  by  Rhumbler  to  changes  in  the  composition  in  the  par- 
ticles through  digestion,  so  that  they  have  a  greater  surface  affinity 
for  the  surrounding  fluids  than  for  the  protoplasm  of  the  cell. 

Phagocytosis  cannot  be  readily  ascribed  to  chemotaxis,  how- 
ever, in  the  case  of  phagocytosis  of  perfectly  insoluble,  chemic- 
ally inert  particles,  such  as  coal-dust.  The  leucocytes  seem  to 
take  up  foreign  bodies  without  reference  to  their  nutritive  value, 
absorbing  India-ink  granules  and  bacteria  impartially  when  they 
are  injected  together,  and  loading  themselves  so  full  of  carmine 
granules  that  they  cannot  take  up  bacteria  subsequently  injected. 
It  is  possible  that  foreign  bodies  first  become  coated  with  a 
layer  of  altered  proteid  which  then  leads  to  phagocytosis,  but 
there  is  no  sufficient  evidence  for  this  surmise. 

Not  only  leucocytes  but  tissue  cells  are  capable  of  moving 
and  performing  phagocytosis  when  properly  stimulated,  and 
apparently  all  or  nearly  all  fixed  cells  may  act  as  phagocytes 
under  some  conditions.  Their  power  of  independent  movement 
is  much  less  than  their  phagocytic  power.  Endothelial  cells 
are  particularly  active  in  phagocytosis,  as  also  are  the  new  meso- 
dermal  cells  produced  in  inflammation.  Apparently  they  obey 
the  same  laws  as  the  leucocytes,  and  not  only  take  up  bacteria, 
but  also  fragments  of  cells  and  tissues,  red  corpuscles,  and  even 
intact  leucocytes  and  other  cells.  Brodie 1  considers  that  phago- 
cytosis by  endothelial  cells  in  lymph-glands  is  the  natural  end  of 
the  leucocytes,  and  red  corpuscles  seem  to  have  a  similar  fate. 

Phagocytosis  is  usually  accomplished  solely  by  the  cytoplasm 
of  the  cells,  the  nuclei  maintaining  a  passive  role  ;  but,  according 
to  Detre  and  Selli,2  the  phagocytosis  of  particles  of  lecithin 

1  Jour,  of  Anat.  and  Physiol.,  1901  (35),  142. 

2  Berl.  klin.  Woch.,  1905  (42),  940. 


PHAGOCYTOSIS  217 

is  accomplished  by  the  nuclei,  which  seem  to  have  a  specific 
affinity  for  this  substance. 

Giant-cell  formation  may  also  be  considered  as  the  result  of 
chemotaxis,  the  cells  moving  toward  the  attracting  particle, 
and  when  the  particle  is  larger  than  the  cells  they  spread  out 
upon  its  surface,  their  cytoplasm  flowing  together  because  of 
altered  surface  tension.  The  peripheral  disposition  of  the 
nuclei  probably  depends  on  the  fact  that  in  ameboid  motion  the 
nucleus  of  the  cell  plays  an  entirely  passive  role,  being  dragged 
along  by  the  cytoplasm,  and  hence  it  is  located  most  remotely 
from  the  attracting  particle.  Digestion  of  materials  taken  into 
a  giant-cell  seems  to  go  on  as  in  the  individual  cells  that 
compose  it.1 

Influence  of  the  Serum  on  Phagocytosis  (Opson^ 
ins).2 — Phagocytosis  of  bacteria  by  leucocytes  seems  not  to  be 
merely  a  reaction  between  the  leucocytes  and  the  bacteria,  as  has 
been  assumed  by  Metchnikoff  and  his  school.  Wright  and 
Douglas 3  have  demonstrated  that  certain  substances  in  the  blood- 
serum  are  necessary  to  prepare  the  bacteria  for  phagocytosis, 
these  substances  being  termed  by  them  "  opsonins."  If  leuco- 
cytes are  washed  free  from  serum  with  salt  solution  and  let 
stand  in  a  test-tube  with  such  bacteria  as  Streptococcus pyogenes, 
Staphylococcus  pyogenes,  B.  typhosus,  B.  coli,  B.  tuberculosis, 
and  various  other  organisms,  no  phagocytosis  occurs.  If,  how- 
ever, some  serum  from  a  normal  or  an  immunized  animal  is 
added  to  the  mixture,  active  phagocytosis  soon  takes  place. 
This  opsonin  is  susceptible  to  heat,  for  if  the  bacteria  are  let 
stand  with  serum  that  has  been  previously  heated  to  60°  for 
ten  minutes,  and  then  placed  with  the  leucocytes,  no  phagocy- 
tosis occurs,  but  if  unheated  serum  is  used,  the  bacteria  will  be 
taken  up  by  the  leucocytes.  These  observations  have  been 
corroborated  and  extended  by  Hektoen  and  Ruediger.4  The 
opsonin  acts  upon  the  bacteria  rather  than  upon  the  leucocytes. 
Certain  salts  were  found  to  reduce  considerably  the  degree 
of  opsonic  action  by  acting  upon  the  opsonin  itself.  What 
changes  the  opsonins  produce  in  the  bacteria  that  makes  them 
capable  of  attack  by  the  leucocytes  is  unknown.  The  effect  of 
negatively  chemotactic  substances  (i.  e.,  substances  preventing 
chemotaxis)  depends  upon  their  destroying  the  opsonin,  accord- 
ing to  the  results  obtained  by  Hektoen.5 

1  See  Faber,  Jour,  of  Path,  and  Bact.,  1893  (1),  349. 

2  See  also  Immunity  against  Bacteria,  Chap.  vi. 
3Proc.  Koyal  Soc.,  1903  (72),  357;  1904  (73),  128. 
*  Jonr.  of  Infectious  Diseases,  1905  (2),  128. 

5  Complete  re'sume'  in  the  Jour.  Amer.  Med.  Assoc.,  1906  (46),  1407. 


218  INFLAMMATION 

Results  of  Phagocytosis. — After  phagocytosis  has  been 
accomplished,  the  fate  of  the  engulfed  object  depends  upon  its 
nature.  If  digestible  by  the  intracellular  enzymes  it  is  soon 
destroyed,  but  in  the  case  of  engulfed  living  cells,  it  seems 
probable  that  they  must  be  first  killed — they  form  no  exception 
to  the  rule  that  living  protoplasm  cannot  be  digested.  This 
brings  forward  the  question  of  so  much  importance  in  the 
problems  of  immunity  :  Do  living  bacteria  enter  phagocytes, 
or  are  they  first  killed  by  extracellular  agencies  before  they  can 
be  taken  up  ?  At  the  present  time  it  seems  to  be  positively 
established  that  leucocytes  do  take  up  bacteria  which  are  still 
viable,  and  which  may  either  grow  inside  the  leucocyte  or  may 
be  destroyed  by  intracellular  processes.1  On  the  other  hand, 
leucocytes  do  not  take  up  extremely  virulent  bacteria,  and  hence 
the  question  as  to  the  relative  importance  played  by  the  leuco- 
cyte and  by  the  body  fluids  is  still  undetermined.  It  is  prob- 
able that  phagocytosis  by  fixed  tissue-cells  is  of  much  less 
importance  in  checking  bacterial  growth  than  is  phagocytosis 
by  leucocytes.  Thus  Ruediger's  experiments  showed  that  emul- 
sions of  organs,  with  the  exception  of  bone-marrow,  do  not 
destroy  streptococci  which  are  readily  destroyed  by  leucocytes. 

Indigestible  substances  may  remain  in  cells,  particularly  in 
fixed  tissue  cells,  for  very  long  periods,  if  the  substances  are 
chemically  inert.  The  leucocytes  seem  to  transfer  the  indiges- 
tible particles  which  they  have  engulfed  to  other  tissues, 
particularly  to  the  lymph-glands  ;  this  is  probably  accomplished 
by  phagocytosis  of  the  ladened  leucocytes  by  the  macrophages 
of  the  lymph  sinuses,  but  how  the  insoluble  particles  are  later 
transferred  to  the  gland  stroma  or  perilymphangial  tissues, 
where  they  are  chiefly  found  in  such  conditions  as  anthracosis, 
etc.,  is  quite  unknown. 

THEORIES  OF  CHEMOTAXIS  AND  PHAGOCYTOSIS 
On  the  assumption  that  leucocytes  obey  the  same  laws  in 
their  motions  as  do  the  amebse,  studies  of  the  latter  and  of 
other  forms  of  protozoa  have  furnished  most  of  the  ideas,  hypo- 
theses, and  theories  of  the  forces  involved  in  leticocytic  activities. 
The  structural  relation  of  the  leucocyte  to  the  ameba  is  striking, 
although,  by  no  means  complete  ;  the  relation  of  their  activities 
is  even  closer.  Each  is  a  microscopic,  independent,  unicellular 
organism,  moving  freely  in  all  directions  by  means  of  pseudo- 
podia  and  protoplasmic  streaming,  taking  other  smaller  bodies 
into  its  substance  and  digesting  them,  reacting  similarly  to  like 
1See  Kuediger,  Jour.  Amer.  Med.  Assoc.,  1905  (44),  198. 


THEORIES  OF  CHEMOTAXIS  AND  PHAGOCYTOSIS   219 

stimuli,  and  containing  similarly  a  nucleus  and  many  granules. 
The  differentiation  of  the  protoplasm  of  the  ameba  into  a  clear 
outer  ectosarc  and  an  inner  granular  endosarc  is  perhaps  an 
important  difference,  but  so  far  as  the  two  forms  of  cells  have 
been  studied,  the  effect  of  this  difference  in  structure  does  not 
seem  to  have  been  considered.  That  the  unicellular  protozoa, 
devoid  of  any  central  nervous  system,  and  without  any  apparent 
co-ordinating  mechanism,  seem  able  to  move  about  in  a  purpose- 
ful way,  going  toward  food  supplies  and  away  from  injurious 
agencies,  toward  or  away  from  light,  heat,  and  chemicals,  has 
long  attracted  the  interest  of  physiologists,  particularly  as  in 
these  single-celled  organisms  we  may  look  for  the  simplest  con- 
ditions of  existence  and  the  most  elementary  life  processes.  It 
seems  absurd  to  imagine  that  a  paramceeium  goes  toward  a 
dilute  acid  because  it  "  likes  it,"  that  an  ameba  rejects  a  piece  of 
glass  because  it  "  does  not  taste  good,"  as  we  explain  similar 
manifestations  in  higher  forms  ;  furthermore,  it  has  been  shown 
by  Verworn  that  minute  enucleated  fragments  of  protozoan  cells 
react  to  stimuli  just  as  does  the  entire  cell,  and,  therefore,  it 
seems  that  the  only  possible  explanation  of  movements  in  proto- 
zoa must  be  a  direct  reaction  of  the  stimulated  part  to  the 
stimulus.  The  nature  of  the  stimulus  and  the  nature  of  the 
stimulated  substance  must  determine  the  nature  of  the  resulting 
reaction,  and  most  of  the  observations  so  far  made  suggest  that 
these  reactions  can  be  explained  according  to  the  known  laws 
of  the  physics  of  fluids.  An  ameba,  or  a  leucocyte,  may  be 
looked  upon  as  a  drop  of  a  colloidal  solution,  surrounded  by  a 
delicate  surface  layer  which  is  more  or  less  readily  permeable  to 
solvents  and  to  substances  in  solution,  and  suspended  in  a  fluid 
of  quite  different  composition. 

Surface  Tension. — Such  a  drop  of  fluid  suspended  in  another  dif- 
ferent fluid  obeys  well-known  laws  of  physics.  The  particles  of  each 
fluid  are  all  under  the  influence  of  a  very  considerable  force,  called  the 
cohesion  pressure,  which  tends  to  draw  them  together  closely.  Within 
the  drop  each  particle  is  subjected  to  this  force  alike  from  all  sides,  so 
that  the  forces  neutralize  one  another,  and  each  particle  is  as  free  as  if 
there  were  no  cohesion  pressure.  But  the  particles  on  the  surface  are 
subjected  to  unequal  pressure,  for  that  of  the  fluid  outside  the  drop  is 
different  from  that  inside,  and  so  the  pressure  on  the  surface  particles  is 
equal  to  the  difference  of  the  cohesion  pressure  of  the  two  fluids  ;  this 
constitutes  the  surface  tension.  It  is  this  tension  that  pulls  in  upon  the 
surface  continually,  causing  it  to  tend  always  to  reduce  the  free  surface 
to  a  minimum,  which  condition  exists  perfectly  in  the  sphere.  The 
amount  of  cohesion  affinity  is  very  different  in  different  fluids,  and  there- 
fore some  have  a  high  surface  tension  and  some  a  low.  When  a  sub- 
stance dissolves  in  another  the  surface  tension  is  a  resultant  of  the  sur- 


220  INFLAMMATION 

face  tension  of  the  two  substances,  and  hence  the  surface  tension  of  a 
liquid  may  be  raised  or  lowered  by  dissolving  various  substances  in  it. 

ARTIFICIAL   IMITATIONS  OF  AMEBOID  MOVEMENT 

Imagining  a  drop  of  fluid  suspended  in  water — let  it  be  a 
drop  of  protoplasm,  or  oil,  or  mercury  ;  the  drop  owes  its  ten- 
dency to  assume  a  spherical  shape  to  the  surface  tension,  which 
is  pulling  the  free  surface  toward  the  center  and  acting  with 
the  same  force  on  all  sides.  The  result  is  that  the  drop  is  sur- 
rounded by  what  amounts  to  an  elastic,  wrell-stretched  mem- 
brane, similar  to  the  condition  of  a  thin  rubber  bag  distended 
with  fluid.  If  at  any  point  in  the  surface  the  tension  is  les- 
sened, while  elsewhere  it  remains  the  same,  of  necessity  the 
wall  will  bulge  at  this  point,  the  contents  will  flow  into  the 
new  space  so  offered,  and  the  rest  of  the  wall  will  contract ; 
hence  the  drop  moves  toward  the  point  of  lowered  surface 
tension.  Conversely,  if  the  tension  is  increased  in  one  place, 
the  wall  at  this  point  will  contract  with  greater  force  than  else- 
where, driving  the  contents  toward  the  less  resistant  part  of 
the  surface,  and  the  drop  will  move  away  from  the  point  of 
increased  tension.  The  resemblance  of  these  changes  of  form 
and  the  type  of  motion  produced  to  ameboid  movement,  is 
apparent,  and  much  experimenting  has  been  done  to  determine 
how  far  the  processes  of  motion  as  shown  by  amebse  and  leuco- 
cytes can  be  reproduced  by  fluid  drops  under  various  conditions 
of  experiment,  and  to  ascertain  if  such  ameboid  movement  of 
living  cells  can  be  entirely  explained  by  the  laws  of  surface 
tension. 

Gad,1  in  1878,  pointed  out  the  resemblance  to  ameboid  motion 
of  the  changes  in  shape  observed  in  drops  of  rancid  oils  in 
weak  alkaline  solution.  These  changes  in  shape  are  due  to 
the  formation  of  soaps  which  lower  the  surface  tension  of  the 
drop  in  places,  so  that  the  fluid  flows  toward  these  places  and 
produces  pseudopodium-like  projections. 

G.  Quincke 2  later  ascribed  the  contractions  and  other  move- 
ments of  ameba  to  alterations  of  the  surface  tension  of  the 
living  substance  in  relation  to  that  of  the  surrounding  medium, 
believing  the  substances  responsible  for  the  alterations  to  be 
albuminous  soaps. 

Biitschli 3  found  that  drops  of  "  foam  structure  "  made  by 
mixing  rancid  oil  and  potassium  carbonate  solution  show 
"protoplasmic  streaming "  when  placed  in  glycerine,  and  that 

'DuBois  Keymond's  Arch.  f.  Physiol.,  1878,  p.  181. 

2  Wiedmann's  Annalen,  1888  (35),  580. 

3  "  Protoplasm,"  translation  by  Minchin,  London,  1894. 


THEORIES  OF  CHEMOTAXIS  AND  PHAGOCYTOSIS   221 

they  exhibit  positive  cheinotaxis  toward  soap  solution  and 
other  chemicals,  the  motion  being  accompanied  by  current  for- 
mation in  the  drops.  The  "  pseudopodia,"  formed  by  the  drops 
also  show  currents  rushing  along  their  axes  and  returning  by 
way  of  the  surface.  Heat  leads  to  increased  activity  of  motion. 
The  motions  were  ascribed  by  Biitschli  to  the  bursting  of  some 
of  the  superficial  globules  of  the  foam,  which  then  spread  over 
the  surface  of  the  drops,  lowering  its  surface  tension  at  the 
point  of  contact.  He  believed  that  ameboid  motion,  likewise, 
depended  upon  rupture  of  surface  globules  of  protoplasm,  for 
the  "  foam  structure "  of  which  he  has  been  the  leading  advo- 
cate. 

Bernstein,1  basing  his  work  on  some  observations  of  Paal- 
zow,  observed  that  a  completely  inorganic  substance,  a  drop  of 
quicksilver,  could  be  made  to  imitate  ameboid  motion  under 
the  influence  of  chemical  changes.  If  near  a  drop  of  quick- 
silver in  a  nitric  acid  solution  a  crystal  of  potassium  dichromate 
is  placed,  as  soon  as  the  yellow  color  made  by  diffusion  of  the 
dichromate  reaches  the  drop,  the  quicksilver  begins  to  show 
motion  and  advances  toward  the  crystal.  This  movement  is 
due  to  local  oxidation  of  the  surface  mercury,  which  lowers  the 
tension  on  that  side  of  the  drop,  toward  which  the  mercury 
then  flows.  If  the  crystal  is  removed,  the  drop  follows,  often 
flowing  about  it  as  if  to  take  it  in,  but  soon  again  withdrawing 
when  the  acid  dissolves  away  the  oxide  formed  on  the  surface, 
only  to  return  again  later.  All  these  movements,  which  may 
be  very  life-like,  are  readily  explained  by  changes  in  surface 
tension  that  take  place  under  the  influence  of  the  bichromate 
and  the  acid,  and  are  unquestionably  referable  to  surface  phe- 
nomena. 

Artificial  Amebse. — By  far  the  most  suggestive  experi- 
ments on  the  simulation  of  ameboid  activity  by  non-living 
substances  are  those  of  Rhumbler  (1898)  in  his  great  work, 
"  Physikalische  Analyse  von  Lebenserscheinungen  der  Zelle."  2 
On  the  assumption  that  the  living  protoplasm  was  but  a  more 
or  less  tenacious  fluid,  following  the  simple  physical  laws  of 
fluids,  especially  in  relation  to  its  surface  tension,  he  devised  a 
number  of  experiments  to  determine  the  correctness  of  these 
views.  An  ameba  may  be  regarded  as  such  a  mass  of  viscid 
fluid,  in  a  medium  in  which  it  is  nearly  or  quite  insoluble  ;  it  is 
also  constantly  undergoing  chemical  changes  within  itself,  and 
taking  substances  from  or  secreting  them  into  the  surrounding 

1Pfliiger's  Arch.,  1900  (80),  628. 

2  Arch,  f,  Entwicklungsmechanik,  1898  (7),  103. 


222  INFLAMMATION 

water.  To  reproduce  partly  these  conditions  a  drop  of  clove 
oil  is  placed  in  a  mixture  of  glycerine  and  alcohol ;  the  alcohol 
and  clove  oil  are  miscible,  the  glycerine  merely  retarding  the 
diffusion.1  Such  a  drop  of  oil  will  move  about,  changing  its 
form  and  sending  out  pseudopodia  much  as  an  ameba  does. 
These  movements  are  undoubtedly  due  to  changes  in  the  surface 
tension  brought  about  by  the  irregular  mixing  of  the  alcohol 
and  the  clove  oil.  The  effect  of  chemotaxis  upon  an  ameba 
can  likewise  be  imitated  with  such  an  "  artificial  ameba."  If 
some  stronger  alcohol  is  carefully  introduced  into  the  fluid  near 
the  drop,  the  surface  tension  on  that  side  will  be  lowered,  and 
the  drop  will  flow  in  that  direction.  The  effect  of  chemical 
changes  within  the  drop  upon  its  motion  may  be  demonstrated 
similarly  by  injecting  a  little  alcohol  into  the  substance  of  the 
drop  near  one  edge — the  drop  will  send  out  a  pseudopodium  on 
that  side,  and  perhaps  flow  along  in  the  direction  of  the  pseudo- 
podium.  We  can  imagine  that  metabolic  changes  in  the  body 
of  an  ameba  may  account  for  many  of  its  seemingly  purposeless 
movements  by  altering  surface  tension  in  some  part  of  its 
circumference.  Thermotaxis,  the  effect  of  heat  in  modifying 
or  impelling  ameboid  motion,  may  be  equally  well  demonstrated 
in  such  an  "  artificial  ameba,"  the  drop  being  "  positively 
thermotactic,"  and  flowing  rapidly  toward  a  heated  point  in  the 
solution,  because  heat  lowers  the  surface  tension. 

Even  as  highly  specialized  a  process  as  the  taking  of  food 
may  be  closely  simulated  experimentally.  Amebse  seem  to 
possess  the  faculty  of  selecting  substances  that  are  suitable  for 
their  food,  crawling  over  particles  of  sand,  wood,  etc.,  and  reject- 
ing them  when  they  are  pushed  against  or  into  the  surface  of 
the  ameba,  which,  however,  readily  takes  up  bacteria,  diatoms, 
algse,  etc.,  digests  them,  and  later  throws  out  the  undigested 
particles.  If  there  is  any  property  of  the  ameba  that  suggests 
voluntary  action,  it  seems  to  be  exhibited  in  the  choice  of  its 
food,  although  this  is  not  so  well  developed  a  selective  process 
as  might  be  expected,  for  amebse  will  take  up  many  harmful 
objects,  and  they  may  be  made  to  fill  themselves  so  full  of  use- 
less substances  that  they  cannot  take  up  food.  However,  a 
drop  of  chloroform  in  water,  which  makes  a  good  artificial 
ameba,  if  "  fed  "  with  various  substances,  will  refuse  some  and 
take  in  others  in  a  surprisingly  life-like  manner.  Pieces  of 
glass  or  of  wood  placed  in  contact  with  the  drop,  exert  no 
influence  ;  if  pushed  into  the  substance  of  the  drop,  they  carry 

1  The  details  of  these  experiments  are  as  given  briefly  by  Jennings,  Jour, 
of  Applied  Microscopy,  1902  (5),  1597. 


THEORIES  OF  CHEMOTAXIS  AND  PHAGOCYTOSIS     223 

the  surface  ahead,  and  on  being  released  they  are  thrown  out 
with  some  force.  If  a  piece  of  shellac,  paraffin,  styrax,  or 
Canada  balsam  be  brought  in  contact  with  the  surface  of  the 
drop,  however,  the  drop  flows  around  it  immediately,  and 
takes  it  within  its  substance,  where  it  is  soon  dissolved.  Even 
more  strikingly  like  phagocytosis  and  intracellular  digestion, 
however,  is  the  result  of  a  similar  experiment  with  a  piece  of 
glass  covered  with  shellac  ;  the  chloroform  "  ameba "  takes  it 
up  as  readily  as  it  does  the  shellac  alone,  but  after  all  the 
coating  is  dissolved  away  the  piece  of  glass  is  then  cast  out  of 
the  drop.  The  resemblance  to  the  engulfing,  digestion,  and 
excreting  of  indigestible  particles  of  bacteria,  etc.,  by  amebse,  is 
so  striking  that  it  seems  impossible  that  there  can  be  any  funda- 
mental differences  in  the  two  processes.  It  will  also  be  noticed 
that  the  drop  takes  in  only  what  it  can  dissolve  and  rejects 
what  it  cannot. 

One  of  the  most  remarkable  actions  of  the  ameba3  which 
seems  almost  certainly  the  result  of  voluntary  action  is  this  : 
Oftentimes  in  feeding,  an  ameba  gets  hold  of  a  suitable  material 
which  is  in  the  form  of  a  long  thread,  much  too  long  for  the 
ameba  to  surround.  It  then  proceeds  to  coil  up  the  thread 
within  its  body,  by  stretching  a  slight  distance  along  the 
thread,  bending  over,  and  forming  a  bend  in  the  thread,  and 
by  repeating  the  process  it  crowds  the  thread  into  a  neat  coil 
within  its  body,  where  it  can  be  digested.  The  process  is  done 
so  systematically  and  with  such  evident  adoption  of  the  means 
at  hand  to  the  desired  end,  that  it  seems  as  if  it  must  be  an 
adaptation  of  the  ameba  to  circumstances,  the  result  of  long 
experience  or  of  heredity.  That  an  artificial  ameba  can  per- 
form the  same  maneuvers  seems  hardly  credible,  but  it  is  readily 
done  with  almost  no  difference  in  detail.  If  the  chloroform 
drop  is  given  a  long  fine  thread  of  shellac,  it  proceeds  to  bend 
the  thread  in  the  middle,  and  to  send  pseudopodia  out  along 
the  thread  to  pull  it  into  the  drop,  coiling  it  up  inside  as  the 
chloroform  softens  the  substance  of  the  thread,  until  it  is  all 
contained  within  the  drop,  provided,  of  course,  that  it  is  not  too 
long  (a  thread  six  times  as  long  as  the  chloroform  drop  may  be 
taken  in  completely).  The  bending  and  coiling  of  the  thread 
in  this  experiment  is  entirely  in  accord  with  the  known  laws 
and  phenomena  of  surface  tension. 

Fully  as  striking  an  ameboid  action  as  the  coiling  up  of  a 
thread  too  long  to  be  taken  in,  is  the  building,  by  some  of  the 
protozoa  closely  related  to  the  ameba  (Difflugid)  of  a  shell 
which  the  animal  seems  to  form  by  cementing  together  grains 


224  INFLAMMATION 

of  sand,  or  diatom  shells,  or  other  suitable  particles.  The  par- 
ticles are  united  so  closely  and  fitted  together  so  well  that  they 
are  almost  perfectly  free  from  crevices.  Even  this  process  is 
accurately  imitated  in  Rhurnbler's  experiments.  If  a  drop  of 
oil  is  mixed  with  fine  grains  of  quartz  sand,  and  dropped  into 
70  per  cent,  alcohol,  the  grains  are  thrown  out  to  the  surface, 
where  they  adhere  to  the  surface  of  the  drop  and  to  one  another 
exactly  as  do  the  particles  in  a  difflugia  shell.  So  well  fitted 
are  the  particles  that  the  artificial  shell  may  remain  intact  for 
months,  and  resemble  the  natural  shell  indistinguishably. 

RELATION   OF   THE   ABOVE    EXPERIMENTS   TO   THE   PHENOMENA 
EXHIBITED  BY  LEUCOCYTES    IN   INFLAMMATION 

The  experiments  cited  indicate  strongly,  to  say  the  least,  that 
amebae,  and  presumably  leucocytes,  react  to  stimuli  of  various 
kinds,  chiefly  through  the  effect  of  these  stimuli  upon  surface 
tension.  The  stimuli  may  come  from  within  the  cell,  being  in 
this  case  the  result  of  changes  in  composition  brought  about  by 
metabolic  processes  ;  such  chemical  products  alter  the  tension  of 
the  surface  nearest  their  point  of  origin,  causing  what  appears 
to  be  spontaneous  motion.  Stimuli  acting  from  without  may 
be  chemical,  thermal,  electrical,  or  mechanical,  but  in  any  event 
they  act  as  stimuli  to  motion  through  their  effect  upon  surface 
tension  ;  if  they  decrease  the  surface  tension  the  cell  goes  toward 
them  ;  if  they  increase  the  tension,  the  cell  moves  away.  The 
behavior  of  leucocytes  in  inflammation  may  be  explained  on 
these  purely  physical  grounds  very  satisfactorily,  as  follows  : 

At  the  point  of  cell  injury  or  of  infection,  substances  are 
produced  that  exert  positive  chemotaxis,  as  can  be  shown  by 
experiments  both  outside  and  inside  the  body ;  these  substances 
are  chemotactic  because  they  influence  the  surface  tension  of  the 
leucocytes,  and  since  with  most  if  not  all  the  products  of  cell 
disintegration  the  effect  is  to  lower  surface  tension,  the  chemo- 
tactic effect  is  positive.  As  the  chemotactic  substances  are 
produced,  they  diffuse  through  the  tissues  until  they  reach  the 
walls  of  a  capillary,  through  which  they  begin  to  pass,  pre- 
sumably most  rapidly  through  the  thinnest  parts  of  the  wall, 
the  "  stomata "  and  intercellular  substance.  The  leucocytes 
passing  along  in  the  bore  of  the  capillary  will  be  touched  by 
the  chemotactic  substances  most  on  the  side  from  which  the 
substances  diffuse  ;  the  surface  tension  will  be  lowered  on  this 
side,  causing  the  formation  of  pseudopodia  and  motion  in  this 
direction.  When  the  leucocytes  come  in  contact  with  the  wall, 
their  surfaces,  because  saturated  with  the  chemotactic  substances, 


THEORIES  OF  CHEMOTAXIS  AND  PHAGOCYTOSIS   225 

will  have  a  tension  much  the  same  as  that  of  the  cells  of  the 
capillary  wall,  which  are  likewise  saturated  with  the  same  sut>- 
stances,  and  the  two  surfaces  will  tend  to  cling  to  one  another; 
explaining  the  phenomenon  of  adhesion  of  leucocytes  to  the 
capillary  wall,  when,  according  to  the  usual  description,  "  the 
leucocytes  behave  as  if  either  they  or  the  capillary  wall  had 
become  sticky."  Surface  tension  of  the  leucocytes  will  be  least 
nearest  the  points  where  the  most  chemotactic  substances  are 
entering  the  capillary,  namely,  the  stomata ;  hence  the  pseudo- 
podia  will  form  in  this  direction  and  flow  through  the  openings, 
the  rest  of  the  cytoplasm  flowing  after  and  dragging  the  nucleus 
along  in  an  apparently  passive  manner.  Since  it  is  the  cytoplasm 
that  seems  to  be  chiefly  affected  in  these  processes,  the  nucleus 
appearing  to  be  rendered  inert  by  its  relatively  dense  and  fixed 
structure,  the  leucocytes  with  most  cytoplasm  are  most  active  in 
emigration,  while  those  with  the  least,  the  lymphocytes,  are 
affected  relatively  little  or  not  at  all. 

Once  through  the  vessel  wall,  the  motion  continues  in  the  same 
manner,  toward  the  side  from  which  the  chemotactic  matter 
comes,  just  as  the  mercury  drop  flows  toward  the  crystal  of 
potassium  dichromate,  or  the  drop  of  oil  flows  toward  the 
alcohol.  If  the  leucocyte  meets  a  substance  that  lowers  its 
surface  tension  sufficiently,  it  will  flow  around  the  object  and 
enclose  it,  just  as  the  chloroform  drop  flows  about  the  piece 
of  shellac  or  balsam  ;  this  constitutes  phagocytosis.  The  motion 
of  the  leucocyte  will  continue  in  a  forward  direction  until  one 
of  several  possible  things  happens  :  (a)  The  leucocyte  may 
reach  a  point  where  the  chemotactic  substances  are  so  thoroughly 
diffused  that  the  effects  on  its  surface  are  the  same  on  all  sides ; 
there  will  then  be  no  tendency  to  move  in  any  direction.  (6) 
It  may  reach  a  material  that  exerts  a  marked  positive  influence 
upon  it,  causing  much  lowering  of  the  surface  tension,  but 
which  is  so  large  that  the  cytoplasm  flowing  along  its  surface 
cannot  surround  it ;  other  leucocytes  will  experience  the  same 
change,  their  cytoplasm  will  fuse  together  because  of  the  equal 
lowering  of  their  surface  tension,  and  soon  we  get  a  mass  of 
leucocytes  with  fused  cytoplasm  surrounding  the  object,  forming 
a  "  foreign  body  giant-cell."  (c)  The  leucocyte  may  reach  a 
place  where  the  concentration  of  the  chemicals  is  so  great  that 
chemical  changes  are  produced  in  its  cytoplasm.  If  these 
changes  are  of  a  coagulative  nature,  the  surface  of  the  cell  will 
be  stiffened  so  that  it  cannot  migrate  further ;  if  of  a  solvent 
nature,  the  leucocyte  is  destroyed,  (d)  It  may  reach  the  margin 
of  an  area  where  the  preceding  leucocytes  have  become  coagu- 

15 


226  INFLAMMATION 

lated  or  otherwise  rendered  immobile,  so  that  they  block  its  path, 
while  it  is  held  fixed  by  the  attraction  on  this  side.  (c  and  d 
explain  the  formation  of  solid  leucocytic  walls  about  areas  of 
inflammation,  and  the  frequent  absence  of  leucocytes  within  the 
central  necrotic  areas.)  (e)  The  formation  of  chemotactic  sub- 
stances may  cease  because  the  substance  causing  the  inflammation 
has  been  used  up,  or  because  the  bacteria  have  been  destroyed, 
or  from  any  of  the  causes  that  terminate  inflammation.  Those 
leucocytes  still  advancing  will  reach  a  point  where  there  is  as 
much  chemotactic  substance  behind  as  in  front — they  will  then 
stop  advancing.  As  the  fluids  exuded  in  the  central  portion 
continue  to  dilute  the  chemotactic  substances  and  wash  them  out, 
there  will  soon  be  less  chemotactic  substance  in  the  center  of  the 
inflamed  area  than  there  is  farther  out,  hence  the  leucocytes 
will  move  away  from  the  center  toward  the  periphery,  following 
the  chemotactic  substances  back  into  the  blood-vessel  and  the 
lymph-stream.  These  are  the  conditions  that  exist  at  the  close 
of  the  inflammatory  process,  which  results  in  the  dispersion  of 
the  leucocytes. 

General  leucocytosis  can  be  explained  equally  well  on  the 
same  grounds.  Chemotactic  substances  from  the  area  of  inflam- 
mation enter  the  blood-stream,  and  so,  in  a  very  dilute  form, 
pass  through  the  bone-marrow.  The  chemotaxis  in  the  blood 
will  be  greater  than  that  of  the  marrow,  and  the  leucocytes  will 
move  toward  and  into  the  blood.  As  long  as  the  blood  contains 
more  chemotactic  substances  than  the  marrow,  leucocytosis  will 
increase,  to  stop  when  the  amount  in  blood  and  marrow  is  alike 
or  when  there  is  less  in  the  blood  than  in  the  marrow. 

Behavior  of  Tissue-cells  and  Formation  of  Giant- 
cells. — The  free  cells  of  the  tissues  involved  in  inflammation 
can,  of  course,  obey  the  same  influences  as  the  leucocytes,  and 
apparently  do  so  in  so  far  as  they  are  not  checked  by  structural 
impediments  to  flowing  motion ;  i.  e.,  the  more  closely  a  cell  is 
related  to  a  simple  drop  of  fluid  protoplasm,  the  more  closely 
does  it  resemble  in  the  simplicity  of  its  reactions  the  "  artificial 
ameba. "  Cells  with  much  cytoplasm  are  best  fitted  to  move 
freely,  as  a  rule,  and  hence  we  see  chiefly  the  large  endothelial 
cells  of  the  lymph  sinuses  and  the  serous  cavities,  and  the  large 
hyaline  and  granular  cells  of  the  blood  acting  as  phagocytes,  for 
phagocytosis  is  no  different  from  ameboid  motion  which  con- 
tinues about  a  particle  until  it  is  surrounded  ;  likewise  we  see 
the  "  epithelioid  "  cells  with  their  abundant  cytoplasm  fusing  to- 
gether to  form  giant-cells.  (Note  that  such  giant-cells  are 
formed  particularly  in  conditions  in  which  the  epithelioid  cell  is 


THEORIES  OF  CHEMOTAXIS  AND  PHAGOCYTOSIS   227 

more  abundant  than  is  the  leucocyte,  e.  g.,  tuberculosis  and 
other  chronic  inflammations.  The  cells  that  fuse  about  an  in- 
fected catgut  ligature  are  the  leucocytes,  for  they  are  most 
abundant  in  such  a  place.)  A  good  illustration,  also,  is  the 
giant-cell  formed  by  fusing  of  leucocytes  about  blastomyces  in 
minute  abscesses  in  the  epithelium  in  blastomycetic  dermatitis ; 
the  epithelial  cells  cannot  flow  or  coalesce  well  because  of  their 
abundance  of  stiff  keratin  and  their  specialized  cell-wall,  and 
hence  do  not  participate ;  the  leucocytes  are  individually  too 
small  to  surround  the  fungus  cells,  and  hence  they  flow  about 
them  in  the  abscess  exactly  as  they  will  do  experimentally  in  a 
test-tube  or  in  a  guinea-pig's  abdomen  (Hektoen).  The  forma- 
tion of  giant-cells  is,  on  this  ground,  but  an  amplification  of 
ameboid  movement  and  phagocytosis.  The  fusing  of  the  in- 
dividual cells  is  due  to  the  lowering  of  their  surface  tension  by 
the  materials  diffusing  from  the  body  which  is  to  be  absorbed, 
until  the  surface  of  each  cell  becomes  alike,  when  the  surface 
tension  at  the  point  where  each  cell  is  in  contact  becomes  zero 
and  the  cytoplasm  runs  together. 

Objections  to  the  above  Hypothesis.— Physical  ex- 
planations of  ameboid  movement  seem  to  fit  very  perfectly  the 
known  facts  concerning  the  actions  of  leucocytes.  There  arise 
but  a  few  difficulties  in  applying  these  laws  to  leucocytic  action  ; 
one  is  the  phagocytosis  of  chemically  inert  bodies,  such  as  coal 
particles,  tattooing  materials,  stone  dust,  etc.  We  know  that 
amebse  also  may  take  up  such  inert  materials,  although  they 
generally  refuse  them,  and  it  is  believed  that  the  particles  exert 
some  local  injury  to  the  cell  wall  that  leads  to  an  alteration  in 
its  tension.  Amebae  seem  also  sometimes  to  excrete  a  sticky 
substance  over  their  surfaces  or  over  the  foreign  matter  that  is 
to  be  engulfed,  which  excretion  seems  to  be  the  result  of  surface 
stimulation.  Possibly  leucocytes  do  the  same.  We  must  bear 
in  mind,  however,  that  the  protoplasmic  cells  have  much  greater 
possibilities  for  action  than  the  "  artificial  ameba,"  since  within 
the  protoplasm  countless  chemical  changes  are  going  on  which 
must  cause  continual  alteration  in  surface  tension  ;  it  is  quite 
possible  that  mere  mechanical  action  may  alter  chemical  action 
at  the  point  of  contact,  so  that  the  injuring  particle  may  become 
surrounded  through  local  liquefaction  of  the  protoplasm. 

With  the  ameba,  unfortunately,  the  explanation  of  all  its 
activities  by  purely  physical  analogies  is  apparently  not  so 
successful.  Although  simple  pseudopodia  may  be  produced  ex- 
perimentally, and  their  formation  explained  readily  on  the  sur- 
face tension  basis,  yet  we  find  many  forms  of  pseudopodia  in 


228  INFLAMMATION 

the  great  family  of  amebse.  Some  of  them  are  branching,  some 
are  fixed  in  extension,  some  have  a  stiff  elastic  axis.  It  would 
also  be  difficult  to  explain  cilia  as  produced  by  changes  in  sur- 
face tension,  yet  we  find  in  some  protozoa  that  pseudopodia  may 
take  on  the  persistence  and  action  of  cilia,  and  that  cilia  may 
seem  to  change  into  pseudopodia.  Jennings  has  made  a  most 
extended  study  of  the  relations  of  the  "  Behavior  of  Lower 
Organisms  "  1  to  the  physical  theories  of  ameboid  motion,  and 
is  unable  to  corroborate  the  claim  that  the  processes  that  go  on 
in  "  artificial  amebse "  exactly  reproduce  those  of  living  ame- 
bse, or  to  accept  the  statement  that  living  protoplasm  behaves 
exactly  as  any  similar  drop  of  fluid  would  under  the  same  con- 
dition. He  states  that  the  currents  set  up  in  artificial  amebse 
by  changes  in  surface  tension  are  not  the  same  as  those  in  living 
ameba,  contrary  to  Rhumbler  and  to  Biitschli.  The  move- 
ment of  ameba,  he  maintains,  is  not  due  to  the  flowing  of  the 
contents  of  the  cell  in  a  central,  axial  current  out  into  the 
pseudopodium  and  back  on  the  sides,  as  occurs  in  the  artificial 
ameba ;  but  rather  to  a  rolling  forward  of  the  upper  surface 
over  the  anterior  edge  to  the  lower  surface,  where  it  becomes 
fixed  to  the  surface  on  which  the  ameba  is  crawling.  The  part 
played  by  surface  tension,  he  claims,  is  in  the  case  of  amebse  a 
very  subordinate  one,  and  it  is  not  sufficient  to  explain  the 
movements  of  the  living  cell. 

However  the  discussion  concerning  the  amebse  may  turn,  it 
must  be  appreciated  that  there  are  some  important  differences 
between  even  the  ameba  and  the  leucocyte.  The  latter  has  by 
far  the  simpler  organization,  and  approaches  in  structure,  and 
presumably,  therefore,  also  in  response  to  stimuli,  more  closely 
to  the  simple  drop  of  colloid  matter.  It  has  no  pulsating 
vacuoles,  no  specialized  pseudopodia,  never  forms  shells  or 
coverings,  and  does  not  conjugate  as  do  the  amebse.  The  ex- 
ternal surface  of  the  leucocyte  is  much  simpler,  an  important 
fact  in  connection  with  surface  tension  effects,  for  in  the  leuco- 
cyte the  surface  seems  to  be  practically  un differentiated,  naked 
protoplasm  ;  whereas  in  ameba  it  is  formed  of  a  well -differentiated 
"  ectosarc, "  which  has  marked  motile  powers,  being  able  to 
contract  sufficiently  to  cut  an  injured  ameba  completely  in  two. 
At  the  very  least  the  surface  tension  explanation  of  leucocytic 
action  agrees  perfectly  ivith  most  of  the  observed  actions  of  leuco- 
cytes, and  it  is  the  only  reasonable  theory  offered.  There  seems 
to  be  no  middle  ground  between  such  a  physical  theory  and  a 

1  Publication  No.  16,  Carnegie  Institute,  Washington,  1904;  also  see  Amer- 
ican Naturalist,  1904  (38),  625. 


SUPPUEATION  229 

metaphysical  theory  which  would  endow  a  single  cell,  without 
organs  or  nervous  system,  with  the  reasoning  powers  of  highly 
developed  animals,  a  position  incompatible  with  the  entire 
evidence  of  experience. 

SUPPURATION 

For  the  formation  of  pus  two  conditions  are  necessary  :  (1) 
the  accumulation  of  leucocytes,  and  (2)  necrosis  and  liquefaction 
of  cells  and  tissue  elements.  Many  leucocytes  may  be  present 
in  a  tissue  without  suppuration  ;  e.  g.,  erysipelas.  Necrosis  of 
cells  with  their  gradual  liquefaction  and  absorption  may  also 
occur  without  suppuration ;  6.  (/.,  infarcts,  aseptic  liquefaction, 
necrosis,  etc.  Hence  for  suppuration  to  occur  there  must  be 
produced  substances  with  positive  chemotaxis,  to  cause  accumu- 
lation of  leucocytes,  for  if  a  necrotic  area  is  devoid  of  leucocytes, 
it  does  not  suppurate ;  e.  g.,  caseous  tubercles.  Secondly, 
necrosis  must  occur,  for  digestion  and  liquefaction  of  living  cells 
and  tissues  does  not  take  place.  Only  substance  meeting  these 
requirements — i.  e.,  causing  positive  chemotaxis  and  cell  necrosis 
— will  cause  suppuration.  Therefore,  although  bacterial  infection 
is  the  usual  cause  of  suppuration,1  it  may  be  produced  by 
many  other  substances,  among  which  the  following  are  best 
known  :  Bacterial  proteins,  even  from  non-pathogenic  bacteria  ; 
oil  of  turpentine,  mercury,  croton  oil,  silver  nitrate  solutions 
(5  to  10  per  cent.),  and  certain  vegetable  proteids  (vegetable 
"  caseins  "). 

An  excellent  example  of  the  importance  of  leucocytes  for  sup- 
purative  softening  is  the  caseous  tubercle,  which  is  usually  free 
from  leucocytes  and  does  not  undergo  suppuration.  If  for  any 
cause  leucocytes  are  attracted  into  the  caseous  area,  softening  and 
pus  formation  promptly  occur.  Hence  Heile 2  found  that  while 
pus  from  a  "  cold  "  tuberculous  abscess  will  not  digest  fibrin  and 
does  not  give  the  biuret  reaction,  both  reactions  appear  after  a 
leucocytosis  has  been  brought  about  by  injection  of  iodoform. 
It  was  formerly  considered  •  that  the  softening  was  due  to  the 
digestive  action  of  the  enzymes  of  the  infecting  bacteria,  many 
of  which  were  known  to  produce  digestive  enzymes  dissolving 
proteid  culture-media  ;  e.  g.,  Staphyloeoccus  pyogenes.  Although 
to  some  extent  these  enzymes  may  be  a  factor  in  causing  the 

1  Buchner  considers  that  bacteria  will  not  produce  suppuration  unless  they 
are  broken  down  so  that  their  pyogenic  proteids  are  released ;  e.  g.,  anthrax 
bacilli  cause  suppuration  when  acting  locally,  as  in  malignant  pustule,  but  not 
when  they  are  causing  septicemia,  because  only  in  the  former  case  are  their 
pyogenic  proteids  liberated. 

2  Zeit.  klin.  Med.,  1904  (55),  508. 


230  INFLAMMATION 

softening  of  the  fixed  tissues  and  of  the  killed  leucocytes,  their 
effect  is  probably  insignificant  as  compared  with  the  enzymes 
liberated  by  the  leucocytes,  as  shown  by  the  production  of  active 
experimental  suppuration  under  aseptic  conditions  with  turpen- 
tine, croton  oil,  etc.1  Suppuration  is,  therefore,  the  result  of 
three  processes:  (1)  Necrosis  of  cells;  (2)  local  accumulation 
of  leucocytes ;  (3)  digestion  of  the  necrotic  cells,  fibrin,  and 
tissue  elements  by  enzymes  which  are  derived  from  three  sources, 
as  follows  :  (a)  the  leucocytes  ;  (6)  the  infecting  bacteria  (if  such 
are  present);  (c)  the  fixed  tissue-cells.  Possibly  small  quanti- 
ties of  enzymes  are  also  introduced  in  the  blood  plasma,  but 
these  are  probably  very  inconsiderable.  Normal  serum,  and 
probably  also  normal  cells,  contain  antibodies  for  the  proteo- 
lytic  enzymes  of  the  leucocytes,  and  hence  neutralization  or 
destruction  of  these  antibodies  may  be  an  important  factor  in 
determining  the  rate  and  amount  of  suppuration.2 

The  proteolytic  enzymes  of  the  leucocytes  and  tissue-cells 
have  been  previously  considered  in  connection  with  the  subject 
of  autolysis  (Chap,  iii),  and  it  is  necessary  here  only  to  call 
attention  to  the  fact  that  these  enzymes  are  of  at  least  two  varie- 
ties :  (1)  Proteolytic  enzymes  of  the  polymorphonuclear 
leucocytes,  which  act  best  in  alkaline  medium  (Opie3);  (2)  auto- 
lytic  enzymes  of  the  tissue-cells,  which  act  best  in  an  acid 
medium  (Hedin,  et  aL).  Possibly  the  mononuclear  leucocytes 
contain,  like  the  tissue-cells,  enzymes  acting  in  an  acid  medium. 
The  antienzymatic  action  of  pus  serum  is  favored  by  an  alka- 
line reation,  but  is  altogether  lost  in  an  acid  medium  (Opie). 

COMPOSITION  OF  PUS 

Because  of  its  method  of  production,  pus  consists  of  the  follow^- 
iug  substances  :  (1)  The  constituents  of  the  exuded  blood  plasma ; 
(2)  the  constituents  of  the  leucocytes  (and  tissue-cells)  that 
exist  free  in  the  pus  ;  (3)  the  products  of  digestion  of  the  pro- 
teids  of  the  leucocytes  and  necrosed  tissues.  All  analyses  of 
pus  that  are  recorded  in  the  literature  are  in  harmony  with  the 
above  statements.  In  general  the  analyses  consider  pus  as  com- 
posed of  two  chief  portions,  the  pus-corpuscles  and  the  pus 
serum.  As  is  to  be  expected,  the  composition  of  pus-corpuscles 
is  simply  that  of  a  large  mass  of  leucocytes,  which  contain 
minute  quantities  of  substances  taken  up  from  the  pus  serum 

1  Apparently  suppuration  may  occur  in  herpes  zoster  vesicles  in  the  absence 
of  bacteria,  according  to  the  findings  of  Kreibich  (Wien.  klin.  Woch.,  1901 


2  See  Opie,  Jour.  Exper.  Med.,  1905  (7),  316). 

3  Jour.  Exper.  Med.,  1906  (8),  410. 


SUPPURATION  231 

by  absorption  and  phagocytosis.     The  old  analyses  of  pus-cor- 
puscles by  Hoppe-Seyler l  are  given  in  the  following  table  : 

TABLE  I. 
Quantitative  Composition  of  Pus-cells  (in  1000  parts  of  the  dried  substance). 

i  II 

Proteids 137.62 ) 

Nuclein       342.57  \-  685.85                673.69 

Insoluble  bodies 205.66  J 

Lecithin \  14000                  75.64 

Fat }  143'83                  75.00 

Cholesterin 74.00  .    .    ,                   72.83 

Cerebrin 51.99  \  10284 

Extractive  bodies 44.33  / 

Mineral  Substances  in  1000  Parts  of  the  Dried  Substance. 


NaCl                                •           •    • 

4.35 

fWPO  ^ 

2.05 

Mff(PO) 

1.13 

FePO            ' 

1.06 

PO, 

9.16 

Na         ...                           ... 

0.68 

K 

.    .'  .    .  trace 

As  abnormal  constituents  of  the  leucocytes  contained  in 
abscesses  may  be  mentioned  glycogen,  fat  (from  phagocytosis 
and  from  "  fatty  degeneration  "  of  the  leucocytes),  and  "  pep- 
tone" (Hofmeister 2). 

Pus  serum  differs  from  blood-serum  chiefly  in  the  substances 
added  to  it  through  the  proteolytic  changes  that  occur  in  the 
pus.  The  fibrinogen  that  escapes  from  the  vessels  into  suppu- 
rating areas  becomes  so  altered  that  pus  will  not  coagulate,  even 
upon  addition  of  fibrin  ferment  (defibrinated  blood).  The 
reaction  of  the  serum  is  usually  slightly  alkaline,  becoming 
strongly  alkaline  if  much  ammonia  is  produced,  which  occurs 
especially  if  there  is  secondary  infection  with  the  organisms  of 
putrefaction.  Sometimes,  however,  lipase  derived  from  either 
bacteria  or  from  the  cells  causes  the  splitting  of  sufficient  amounts 
of  fatty  acids  from  the  fats  to  make  the  reaction  acid ;  lactic 
and  other  fatty  acids  are  also  sometimes  formed.  Presumably 
the  nature  of  the  infecting  organism  will  modify  the  reaction, 
for  some  (e.  g.,  staphylococcus)  cause  an  acid  formation  in  media, 
while  others  (e.  g.,  pyocyaneus)  causes  an  alkaline  reaction. 
Hoppe-Seyler' s  analyses  of  pus  serum  gave  the  following  results, 
which  show  no  considerable  deviation  from  the  composition  of 
blood  plasma,  except  in  an  increased  proportion  of  fatty  matter 
and  extractive  substances. 

1  Med.-Chem.  Untersuchungen.  2  Zeit.  physiol.  Chem.,  1880  (4),  268. 


232  INFLAMMATION 


TABLE  II. 

Quantitative  composition         Plasma 
of  pus  serutn.  (normal). 

I  II  III 

Water 913.7  905.65  908.4 

Solids 86.3  94,35  91.6 

Proteids 63.23  77.21  77.6 

Lecithin 1.50  0.56  ^ 

Fat 0.26  0.29  [•  1.2 

Cholesterm 0.53  0.87  J 

Alcohol  extractives 1.52  0.73  \ 

Water  extractives 11.53  6.92  /  4'° 

Inorganic  salts 7.73  7.77  8.1 

Quantitatively  the  chief  abnormal  constituent  of  pus  serum 
is  the  so-called  "  pyin  "  of  the  older  writers,  which  is  nucleo- 
proteid  derived  from  the  decomposing  leucocytes,  and  hence 
increasing  in  amount  progressively  with  the  age  of  the  pus ;  it 
is  characterized  by  its  insolubility  in  acetic  acid.  The  same 
substance  is  found  more  abundantly  in  the  entire  pus,  on 
account  of  the  presence  of  the  cells,  and  when  treated  with 
10  per  cent.  NaCl  solution  it  forms  a  stringy  mass  which  was 
formerly  called  "  Rovida's  hyalin  substance."  In  the  pus  serum 
are  found  all  the  other  constituents  of  the  leucocytes,  includ- 
ing particularly  lecithin,  cholesterin,  fats  (and  soaps),  cerebrin, 
"  jecorin,"  and  glycogen  ;  and  also  the  usual  components  of  the 
blood-serum  as  well  as  some  small  quantities  of  pigment  derived 
from  decomposed  red  corpuscles. 

The  products  of  autolysis  are  of  particular  interest,  and  they 
are  found  in  varying  amount,  but  usually  less  abundantly  than 
might  be  expected,  probably  because  of  their  solubility  and  con- 
sequent rapid  absorption.  Albumoses  and  peptone  seem  to  be 
constantly  present  (Shattock  *  ).  The  common  occurrence  of 
albumosuria  during  suppuration  presumably  depends  on  the 
absorption  of  digestion  products  from  the  pus,2  but  true  peptone 
has  not  been  satisfactorily  identified  in  the  urine.  Leucin  and 
tyrosin  have  also  frequently  been  found  in  pus,  but  Taylor* 
could  find  no  workable  traces  of  either  monoammo-  or  polyamino- 
acids  in  a  liter  of  pus,  which  may  depend  on  their  having  been 
either  absorbed  or  transformed  into  ammonium  compounds.  From 
the  nucleoproteids  purin  bodies  are  formed  and  may  be  found 
in  the  pus.  The  relation  of  the  purin  bases  to  local  leucocy- 
tosis  is  shown  by  Heile,4  who  found  in  cold  tuberculous  abscesses 

1  Trans.  London  Path.  Soc.,  1892  (43),  225. 

2  Literature    on   albumosuria,   see  Yarrow,  Amer.    Med.,    1903    (5),  452; 
Elmer,  ibid.,  1906  (11),  169  ;  Senator,  International  Clinics,  1905  (IV)  series  14r 
p.  85.     See  also  "  Albumosuria,"  Chap.  xix. 

3  Univ.  of  California  Publications  (PathoL),  1904  (1),  46.  4  Loc.  cit. 


SPUTUM  233 

a  proportion  of  purin  bases  equal  to  0.5  per  cent.,  in  similar 
abscesses  after  injection  of  iodoform,  1.57,  and  in  acute  sup- 
puration, 10.7.  Spermin  crystals  are  also  occasionally  found 
in  old  pus  collections.1  Free  fatty  adds  and  volatile  fatty  acids, 
such  as  butyric,  lactic,  valerianic,  and  formic,  may  also  be  pres- 
ent. Products  of  bacterial  activity,  such  as  bacterial  proteids 
and  pigments  (e.g.,  pyocyanin),  may  also  be  present.  (See  also 
discussion  of  "  Autolysis  of  Exudates,"  Chap.  iii). 

All  the  numerous  enzymes  of  the  blood  plasma,  the  leucocytes 
and  the  tissue-cells  are  present  in  pus.  Thus  Achalme 2  found 
evidence  of  the  presence  of  the  following  enzymes  in  pus : 
proteolytic  enzymes,3  lipase  (splitting  monobutyrin),  diastase, 
rennin  (coagulating  milk),  gelatinase,  catalase,  and  oxidase,  the 
last  being  very  abundant.  These  seem  to  exist  chiefly  in  the 
leucocytes,  the  pus  serum  being  quite  free  from  them.  No 
evidence  could  be  found  of  enzymes  acting  on  amygdalin,  sac- 
charose, inulin,  or  lactose.  Fibrin  ferment  is  said  to  be  absent 
from  pus,  which  is  quite  surprising  in  view  of  the  fact  that  this 
enzyme  is  generally  considered  as  being  derived  chiefly  from 
the  leucocytes. 

SPUTUM  ^ 

The  chemistry  of  sputum  may  be  properly  considered  in  this 
connection.  In  reaction,  sputum  is  ordinarily  alkaline,  but  in 
case  of  marked  bacterial  decomposition  in  cavities  the  reaction 
may  become  acid.  Its  specific  gravity  varies  from  1.008  to 
1.026,  usually  varying  directly  with  the  number  of  leucocytes ; 
the  average  specific  gravity  is  about  1.013.  The  greenish  color 
frequently  observed  depends  generally  upon  blood-pigment 
(except  in  case  of  icterus),  although  in  some  instances  the  pig- 
ment is  of  bacterial  origin.  Renk 5  has  studied  the  proteids  of 
sputum  with  special  reference  to  the  loss  of  proteid  to  the  body 
and  its  relation  to  cachexia.  In  three  patients  (consumptives) 
studied,  the  daily  amount  of  sputum  of  two  averaged  145 
grams  for  each  ;  for  the  third  it  was  82  grams.  This  contained 
(average)  5  to  6  per  cent,  of  solids  ;  including  mucin,  2-3  per 
cent. ;  proteid,  0.1-0.5  per  cent.  ;  fat,  0.3-0.5  per  cent. ;  ash, 
0.8-0.9  per  cent.  The  daily  loss  of  nitrogen  was  0.75  gram, 

1  See  Williams,  Boston  Med.  and  Surg.  Jour.,  1901  (145),  355. 

2  Compt.  Rend.  Soc.  BioL,  1899  (51),  568. 

3  Concerning  proteolytic  enzymes  of  pus  see  Opie,  Jour.  Exper.  Med.,  1906 
(8),  410. 

*  Complete  bibliography  given  by  Ott,  "  Chem.  Pathol.  der  Tuberc.,"  Berlin, 
1903. 

5Zeit.f.  BioL,  1875  (11),  102. 


234 


INFLAMMATION 


which  equals  about  6  per  cent,  of  the  total  daily  nitrogen  out- 
put of  persons  under  condition  of  starvation.1  Wanner 2  found 
characteristic  variations  in  the  amount  of  proteid  in  sputum 
from  different  conditions,  as  follows :  in  bronchitis  the  amount 
of  proteid  is  very  small ;  in  bronchiectasis  proteid  is  present, 
but  the  amount  of  uncoagulable  nitrogen  (due  to  autolysis)  is 
relatively  large;  in  phthisis  as  well  as  in  bronchiectasis  the 
amount  of  proteid  does  not  exceed  1  per  cent.,  in  pneumonia 
it  may  reach  3  per  cent.,  but  it  is  highest  in  pulmonary  gan- 
grene. Any  proteid  content  that  causes  more  than  a  slight 
turbidity  on  boiling  indicates  an  inflammation ;  e.  g.,  in  case  of 
doubt  between  a  diagnosis  of  pneumonia  and  infarct  a  high 
proteid  content  speaks  for  the  former.  The  mucin  of  sputum 
yields  33.6  per  cent,  of  glucosamin  when  split  with  HC1,  which 
gives  an  index  of  the  quantity  of  mucin ;  this  is  highest  in 
chronic  bronchitis  and  lowest  in  pneumonia  and  phthisis. 
Kossel  found  0.1—0.33  gm.  of  nucleins  in  the  sputum  daily. 

The  following  table  by  Bokay  (taken  from  Ott)  gives  the 
proportion  of  the  organic  constituents  of  sputum  in  parts  per 
thousand: 

TABLE  III. 


Bronchitis 
in 
typhoid. 

Fibroid 
phthisis. 

Phthisis, 
early,  in 
apex. 

Phthisis, 
cavities. 

Phthisis, 
advanced. 

Phthisis, 
advanced. 

Fatty  acids  as  fat 

0.224 

0.845 

0.462 

2.468 

3.468 

9.725 

Free   fatty    acids 

trace 

0.184 

0.521 

0.370 

0.307 

0.902 

Soaps  

traces 

0.380 

0.430 

0.537 

0.516 

3.973 

Cholesterin  . 

traces 

0.4 

1.617 

0.172 

1.160 

0.141 

Lecithin  .    . 

traces 

traces 

1.543 

1.165 

1.245 

Nuclein    .    . 

traces 

0.102 

. 

0.260 

0.489 

Proteid  ... 

0.898 

2.040 

•    • 

4.430 

3.455 

5.115 

On  account  of  the  digestion  of  the  exudates  by  the  leuco- 
cytes, sputum  contains  proteoses,  peptones,  and  amino-acids, 
generally  in  proportion  to  the  richness  of  the  exudate  in  leuco- 
cytes; they  are,  therefore,  most  abundant  in  pneumonia.  Simon3 
found  considerable  albumose  in  phthisical  sputum,  but  no  nucleo- 
histon  or  free  histon.  Staffregen,  however,  could  find  no  true 
peptone  in  phthisical  sputum,  but  Stadelmann 4  found  that  such 

1  Plesch  (Zeit.  exp.  Path.  u.  Ther.,  1906,  Bd.  iii,  July)  found  that  4.8  per 
cent,  of  all  the  absorbed  calories  were  lost  in  the  sputum  in  an  advanced  case 
of  phthisis. 

2  Deut.  /Arch.  klin.  Med..  1903  (75),  347. 

8  Arch.  exp.  Path.  u.  Pharm.,  1903  (49),  449. 
4  Zeit.  klin.  Med.,  1889  (16),  128. 


PROLIFERATION  AND  REGENERATION 


235 


sputum  contained  enzymes  hydrolyzing  fibrin,  and  attributed 
this  largely  to  bacteria. 

The  amount  of  fats  seems  to  depend  directly  upon  the  num- 
ber of  pus-corpuscles  and  the  age  of  the  pus  (i.  e.,  the  amount 
of  fatty  degeneration).  Jacobson  found  from  0.08  to  1.6  grams 
of  fatty  matter  per  day,  containing  on  an  average  14.76  per 
cent,  of  soaps,  15.79  per  cent,  of  higher  fatty  acids,  0-10  per 
cent,  of  water-soluble  fatty  acids,  13.58  per  cent,  lecithin,  and 
10.49  per  cent,  cholesterin. 

As  to  the  inorganic  substances,  Bamberger  found  two  types 
of  sputum,  catarrhal  and  inflammatory.  In  the  inflammatory 
there  is  a  deficiency  in  alkali  phosphate,  SO3  constitutes  more 

than  8  per  cent,  of  the  salts,  and  the  ratio,  ^?  equals  — .      In 

JXj^  -*-^- 

catarrhal  sputum  the  alkali  phosphates  constitute  10-14  per 
cent.,  *^£  =  |^,  and  the  SO3  is  from  0.6-1.2  percent.  Chlo- 
rine is  about  the  same  in  both  forms.  The  results  of  his  anal- 
yses are  shown  in  the  following  table  : 

TABLE  IV. 


Chronic 
phthisis. 

Acute 
phthisis. 

Water  

94.55 

93.38 

Organic    matter      >    

4.67 

6.88 

Inorganic  salts     

078 

074 

One  hundred  parts  of  the  salts  contain  : 
Chlorine    

3578 

33.40 

SO,     

0.70 

0.80 

P,OS   

1305 

14.15 

K20     , 

2407 

1999 

Na2O  

2790 

31.69 

Calcium  phosphate  

1.63 

4321 

Iron  phosphate    

0.09 

014 

Magnesium  phosphate    
Ca  and  Mg  carbonate  and  sulphate 

1.20 
1  74 

022 

Silicic  acid   .    . 

09 

03 

PROLIFERATION    AND   REGENERATION 

The  factors  that  incite  cells  to  proliferate,  as  well  as  those 
that  cause  the  cessation  of  proliferation  after  it  has  once  started, 
are  too  entirely  unknown  to  permit  of  speculation  as  to  their 
exact  nature.  It  seems  probable,  however,  that  they  are,  as 

1  Including  magnesium. 


236  INFLAMMATION 

Ziegler  says,  "  identical  with  the  stimuli  which  excite  or  increase 
functional  and  nutritive  activity,"  and  these  are  certainly  in  many 
instances  of  chemical  nature.  Thus  the  application  of  various 
irritating  substances  in  not  too  concentrated  a  form  (e.  g.,  paint- 
ing the  skin  with  iodin)  may  lead  to  proliferation  without  causing 
discernible  degeneration  of  the  cells.  Mallory's  1  observations 
on  the  phenomena  of  proliferation  and  phagocytosis  show  that 
the  same  bacterial  products  which  destroy  the  cells  when  con- 
centrated, when  sufficiently  dilute  cause  proliferation  of  similar 
cells.  Many  other  instances  of  proliferation  in  response  to 
chemical  stimuli  might  be  cited,  but  in  nearly  all  cases  it  is 
extremely  difficult  to  determine  that  the  proliferation  is  not, 
after  all,  reparative  in  compensation  for  degenerative  changes, 
and,  therefore,  possibly  obeying  some  other  biological  law  than 
that  of  a  simple  reaction  to  a  chemical  stimulus. 

Although  proper  nutrition  is  necessary  for  cell  proliferation, 
yet  it  does  not  seem  that  excessive  nourishment  can  lead  to 
excessive  cell  multiplication,  or  by  itself  cause  cell  proliferation 
to  take  place.  Oxygen  and  certain  inorganic  salts  are  essential 
for  cell  division  even  in  the  lowest  forms,  and  among  such 
simple  organisms  as  sea-urchins  and  certain  other  marine  forms 
segmentation  of  the  unfertilized  ova  may  be  incited  by  changes 
in  osmotic  concentration,  leading  eventually  to  formation  of 
perfect  larvae  (J.  Loeb,  et  al.2).  Potassium  salts  seem  to  be 
particularly  important  for  proliferating  cells,  and  Beebe  and 
also  Clowes  and  Frisbie3  have  found  that  actively  growing 
malignant  tumors  are  rich  in  potassium  and  poor  in  calcium, 
whereas  in  slow-growing  tumors  the  reverse  is  the  case.  Denn- 
stedt  and  Rumpf 4  also  found  that  in  hypertrophy  of  the  heart 
the  amount  of  potassium  is  increased,  while  in  chronic  degenera- 
tion of  the  myocardium  the  calcium  and  magnesium  are  usually 
increased. 

Chemical  studies  of  proliferation  are  lacking,  except  in  regard 
to  the  development  of  the  embryo,  etc.  New  tissues  differ 
from  adult  tissues  in  having  a  large  proportion  of  water,  and  in 
having  a  larger  proportion  of  the  "  primary  "  cell  constituents 
and  a  smaller  proportion  of  the  various  secondary  constituents, 
since  these  last  are  largely  products  of  the  activity  of  the  adult 
cell.  Of  the  primary  constituents,  the  proportion  of  the  nucleo- 
proteids  is  particularly  high,  and  a  number  of  interesting  facts 

1  Jour.  Exp.  Med.,  1900  (5),  15. 

2  See  J.  Loeb,  Studies  in  General  Physiology,  Chicago,  1905. 
3 See  "Tumors,"  Chap.  xvii. 

4Zeit.  klin.  Med.,  1905  (58),  84. 


PROLIFERATION  AND  REGENERATION  237 

concerning  the  nucleoproteids  in  cell  division  have  been  deter- 
mined. Most  important,  perhaps,  are  the  classical  observations 
of  Miescher,  who  found  that  during  the  migration  of  salmon 
up  stream  to  the  spawning  grounds,  during  which  time  no  food 
is  taken,  the  proteids  of  the  muscular  tissue  become  largely 
transformed  into  the  protamin  type  of  proteid  (characterized  by 
containing  large  proportions  of  the  polyamino-acids,  such  as 
arginin,  histidin,  and  lysiu * ),  which  unite  with  nucleic  acids  to 
form  the  abundant  nucleoproteid  of  the  spermatozoa  and  ova. 
Whether  such  a  transformation  of  proteids  occurs  in  mamma- 
lian cells  during  cell  multiplication  cannot  be  stated,  but 
certainly  from  some  source  an  additional  supply  of  nucleo- 
proteid is  derived.  The  nucleoproteids  during  karyokinesis 
undergo  a  chemical  change  in  that  they  become  of  a  more  acid 
type  (presumably  through  splitting  off  of  part  of  the  proteids 
from  the  nucleic  acid),  which  results  in  the  characteristic  increase 
in  affinity  for  basic  dyes.  This  suggests  the  participation  of  an 
enzyme  in  the  process  of  karyokinesis,  just  as  there  seems  to  be 
in  the  production  of  pycnosis  in  degenerating  cells,  but  there 
seems  to  be  no  conclusive  evidence  on  this  point.  Gies2  could 
find  no  enzyme  in  spermatozoa  that  incites  cell  division  in  the 
ova  of  sea-urchins  (Arbauid). 

In  metaplasia  we  have  what  may  be  interpreted  as  a  chemical 
alteration  due  to  mechanical  stimuli,  e.  g.,  the  formation  of 
keratin  by  cells  that  ordinarily  do  not  do  so ;  the  deposition  of 
calcium  salts  and  osteoid  transformation  of  connective  tissue  in 
rider's  bone,  etc.  That  such  is  the  case,  however,  cannot  be 
positively  stated  from  the  evidence  at  hand. 

1  Concerning  protamins,  see  re"sum£  by  Kossel,  Biochem.  Centr.,  1906  (5), 
1  and  33. 

2  Amer.  Jour.  Physiol.,  1901  (6),  54. 


CHAPTER    XI 

DISTURBANCES  OF  CIRCULATION  AND  DISEASES 
OF  THE  BLOOD 

THE   COMPOSITION   OF  THE   BLOOD 

THE  function  of  the  blood  being  to  maintain  an  equilibrium 
in  the  temperature,  chemical  composition  and  osmotic  pressure 
between  all  parts  of  the  body,  it  follows  that  it  is  never  of 
exactly  the  same  composition  in  any  two  places  or  at  any  two 
times.  To  the  extent  that  every  tissue  is  continually  giving 
off  something  to  the  blood,  we  may  consider  that  every  organ 
is  a  factor  in  its  formation,  and  as  a  result  of  this  multiplex 
origin  of  the  blood,  the  substances  it  may  contain  are  beyond 
enumeration.  There  are  probably  but  few  chemical  substances 
occurring  in  the  tissue-cells  that  do  not  also  occur  in  greater  or 
less  amount  in  the  blood.  In  addition  to  these  there  are  also 
the  substances  characteristic  of  the  blood  itself,  besides  a  host 
of  substances  of  unknown  nature,  apparently  manufactured  in 
response  to  the  stimulation  of  substances  entering  the  body  from 
outside ;  for  we  find  that  the  blood  of  every  adult  individual 
contains  substances  that  make  him  immune  to  a  multitude  of 
diseases  that  he  has  had  in  childhood,  as  well  as  substances 
that  in  later  life  protect  him  to  a  greater  or  less  degree  from 
infection  by  such  organisms  as  the  colon  bacilli  of  his  intestine, 
the  pneumococci  and  streptococci  in  his  throat,  etc.  We  have 
learned  of  these  defensive  substances  within  very  recent  times, 
and  also  of  the  "  antienzymes  "  that  possibly  protect  the  blood 
from  the  digestive  enzymes  of  the  body  cells.  What  other 
substances  of  importance  we  may  yet  find  in  the  blood  is 
an  open  question.  There  are  no  apparent  limits  to  the 
possibilities  of  the  study  of  the  blood,  for  it  represents  a 
little  of  every  organ,  and  a  good  deal  that  is  characteristic  of 
itself. 

In  discussing  briefly  the  substances  that  have  been  isolated 
from  the  normal  blood,  before  considering  the  changes  that 
occur  in  it  during  pathological  conditions,  we  may  roughly 
divide  the  blood  into  the  formed  elements  and  the  plasma  in 
which  they  are  suspended. 

238 


THE  COMPOSITION  OF  THE  BLOOD  239 

The  Formed  Elements. — By  weight,  the  red  corpuscles  constitute 
from  40  to  50  per  cent,  of  the  blood,  the  percentage  varying  under  dif- 
ferent conditions,  while  the  total  weight  of  the  leucocytes  and  platelets 
is  insignificant.  The  hemoglobin  constitutes  from  86  to  94  per  cent,  by 
weight  of  the  solids  of  the  red  corpuscles,  but  the  physical  and  chemical 
relations  that  it  bears  to  the  stroma  of  the  corpuscles  are  as  yet  undeter- 
mined (see  ' '  Hemolysis  ").  Of  the  remaining  constituents  of  the  corpus- 
cles, from  5  to  12  per  cent,  consist  of  proteids,  probably  chiefly  globulins  and 
nucleoproteids ;  0.3  to  0.7  per  cent,  of  lecithin;  and  about  0.2  to  0.3  per 
cent,  of  cholesterin  (Hoppe-Seyler).  The  outer  coat  of  the  red  corpuscles 
does  not  seem  to  be  equally  permeable  for  all  substances,  and  therefore 
we  find  the  composition  of  the  fluid  portion  of  the  cell  quite  different 
from  that  of  the  plasma  about  it.  The  salts  of  the  corpuscles  consist 
largely  of  potassium  phosphate,  a  little  sodium  chloride,  some  magnesium, 
but  no  calcium,  which  is  quite  different  from  their  proportion  in  the 
plasma.  Probably  many  of  the  other  constituents  of  the  plasma, 
especially  urea,  penetrate  the  red  corpuscles  to  a  greater  or  less  degree, 
but  most  of  them,  particularly  the  sugar,  remain  chiefly  in  the  plasma. 

Hemoglobin,  the  most  characteristic  constituent  of  all  the  heteroge- 
neous components  of  the  blood,  is  a  compound  proteid,  and  probably 
exists  combined  with  some  other  constituent  of  the  corpuscle>  most 
probably  the  lecithin.  It  splits  up  readily  into  a  proteid,  globin,  and  an 
iron-containing  substance,  hemochromogen,  which  readily  takes  up  oxygen 
to  form  hematin.  Only  about  4  to  5  per  cent,  of  the  hemoglobin  is 
hemochromogen,  and  iron  constitutes  but  about  0. 4  per  cent.  Hematin 
may  be  further  split  up  into  other  substances,  which  will  be  considered 
in  the  discussion  of  ' '  Hemorrhage. ' ' 

The  leucocytes  consist  chiefly  of  nucleoproteids,  with  probably  some 
globulin,  and  they  also  contain  glycogen,  lecithin,  and  cholesterin.  The 
blood-platelets  are  believed  to  be  largely  nucleoproteid,  but  little  is  known 
of  their  actual  composition. 

Blood  plasma  differs  from  blood-serum  in  that  the  latter  is  formed 
from  the  former  through  the  conversion  of  the  fibrinogen  into  fibrin. 
Serum,  therefore,  contains  no  fibrinogen,  but  more  fibrin  ferment ;  other- 
wise it  is  practically  the  same  as  the  plasma. 

Proteids. — Fibrinogen  has  the  general  properties  of  a  globulin,  with 
also  a  peculiar  tendency  to  go  into  the  insoluble  form,  fibrin.  (This 
process  will  be  discussed  under  "  Thrombosis."}  In  the  plasma  are  also 
other  globulins,  one  soluble  in  water  (pseudo- globulin),  the  other  insoluble 
in  water  (euglobulin}.  /Serum-albumin,  another  proteid  of  the  plasma, 
probably  consists  of  two  or  more  varieties  of  albumin.  There  are  also 
nucleoproteids  (prothrombin)  and  non-coagulable  proteids,  which  being 
poorly  understood  have  been  variously  considered  as  glycoproteids,  or 
mucoids,  or  albumoses. 

Other  Constituents. — The  fat  of  the  plasma  varies  much  according  to 
the  time  which  has  elapsed  after  the  taking  of  food  ;  in  fasting  animals 
it  amounts  to  from  0. 1  to  0. 7  per  cent.  The  sugar  fluctuates  less,  being 
normally  about  0. 1  per  cent. ,  while  the  urea  has  been  estimated  at  0. 05 
per  cent.  Most  of  the  sugar  is  dextrose  ;  but  probably  there  is  some 
levulose,  possibly  some  pentose  and  other  forms,  and  possibly  also  sugar 
combined  with  lecithin  (jecorin]  or  other  substances.  Soaps,  cholesterin, 
and  lecithin  also  exist  free  in  the  plasma. 

Plasma  differs  strikingly  from  the  corpuscles  in  that  its  inorganic 
substances  are  chiefly  sodium  and  chlorine,  while  potassium  and  phos- 


240  DISTURBANCES  OF  CIRCULATION 

phoric  acid  are  almost  entirely  absent.  Another  important  fact  is  that 
when  the  plasma  is  combusted,  the  acid  radicals  remaining  do  not  suffice 
to  balance  the  bases,  indicating  that  much  of  the  inorganic  bases  is 
joined  with  organic  substances,  probably  as  ion-proteid  compounds. 
The  alkali  joined  to  the  proteid  is  non-diffusible,  and  constitutes  about 
five-sixths  of  the  total  alkali. 

The  concentration  of  the  electrolytes  of  the  blood  has  been  deter- 
mined by  ascertaining  the  lowering  of  the  freezing-point,  which  in 
human  blood  averages  about  0.526°;  this  corresponds  closely  to  the  effect 
of  a  salt  solution  of  0. 9  per  cent,  strength.  About  three- fourths  of  the 
dissolved  molecules  of  the  blood-serum  are  electrolytes,  and  about  three- 
fourths  of  these  are  molecules  of  NaCl,  most  of  which  are  in  the  dis- 
sociated state.1 

Enzymes. — A  large  number  of  enzymes  exist  in  the  blood,  the  follow- 
ing having  been  detected  :  diastase,  glucase,  lipase,  thrombin,  rennin,  and 
proteases.  The  proteases  are  held  in  check  to  a  large  extent  by  "  anti- 
ferments"  that  are  also  present  (see  "Enzymes,"  p.  72).  In  relation  to 
the  antiferments  are  the  innumerable  antibodies  that  exist  normally  in 
the  serUm  for  foreign  proteids,  foreign  cells,  and  for  bacteria  and  their 
toxins,  as  well  as  those  resulting  from  reaction  to  infection,  etc. 

The  proportions  in  which  the  constituents  of  the  plasma  normally  occur 
have  been  determined  by  Hoppe-Seyler  and  by  Hammarsten  as  follows : 2 

TABLE  I. 

No.  1.  No.  2. 

Water 908.4  917.6 

Solids 91.6  82.4 

Total  proteids 77.6  69.5 

Fibrin 10.1  6.5 

Globulin 

Seralbumin 24.6 

Fat       1.2] 

Extractive  substances 4.0  I  -ion 

Soluble  salts 6.4  [ 

Insoluble  salts 1-7  J 

No.  1  is  an  analysis  by  Hoppe-Seyler. 

No.  2  is  the  average  of  three  analyses  made  by  Hammarsten. 

Alkalescence. — It  is  very  difficult  to  determine  the  exact 
alkalinity  of  the  blood  plasma.  If  we  titrate  with  an  acid,  we 
liberate  much  of  the  alkali  from  the  proteids,  dissociate  all  the 
Na2CO3  present,  as  well  as  the  NaHCO3  and  the  sodium  phos- 
phate, and  find  in  this  way  that  the  entire  fresh  blood  contains 
neutralizable  alkali  corresponding  to  a  solution  of  Na2CO3  of 
about  0.443  per  cent,  strength  (Strauss).  In  other  words,  the 
blood  has  a  quantity  of  alkali  in  combination  that  can  be  drawn 

1  Concerning  relation  of  conductivity  to  freezing-point   see  Wilson,  Amer. 
Jour,  of  Physiol.,  1906  (16),  438. 

Concerning  the  viscosity  of  the  blood  see  Burton-Opitz,  Pfl tiger's  Arch.,  1906 
(112),  189;  and  Determann,  Zeit.  klin.  Med.,  1906  (59),  H.  2-4. 

2  For  complete  analyses  of  the  blood  see  Abderhalden,  Zeit.  physiol.  Chem., 
1898  (25),  106. 


ALKALINITY  OF  THE  BLOOD  241 

upon  to  neutralize  acids  to  the  extent  indicated  by  the  above 
figures.  The  real  alkalinity  of  a  fluid,  however,  is  dependent 
upon  the  number  of  free  OH  ions  in  the  solution  ;  and  Hober  has 
determined  by  physico-chemical  methods  that  the  concentration 
of  OH  ions  in  blood  is  but  little  greater  than  in  distilled  water.1 
The  alkali  of  the  blood  exists  in  part  as  alkaline  salts, 
carbonate  and  phosphate  (the  diffusible  alkali),  and  partly 
combined  with  proteid  (non-diffusible  alkali).  As  the  corpuscles 
are  richer  in  diffusible  alkali  than  the  plasma  or  serum,  the 
number  of  corpuscles  modifies  the  alkalinity  of  the  blood 
decidedly.  Much  importance  is  attached  to  the  question  of  the 
alkalinity  of  the  blood  for  two  reasons  : 2  first,  in  certain  con- 
ditions of  disease  the  blood  contains  so  much  of  organic  acids  that 
the  alkali  is  partly  saturated  and  the  power  of  the  blood  to  carry 
CO2  is  lessened,  with  serious  results  (see  uAcid  Intoxication/' 
Chap,  xviii)  ;  and,  second,  the  bactericidal  power  of  the  blood 
is  found  to  vary  according  to  its  alkalinity.3  In  fact,  metabolic 
activity  seems  generally  to  be  favored  by  certain  degrees  of 
alkalinity ;  for  exampte,  J.  Loeb 4  found  that  sea-urchin  eggs 
develop  with  much  greater  rapidity  if  a  small  amount  of  OH 
ions  is  free  in  the  sea-water.  It  is  stated  that  in  febrile  con- 
ditions the  alkalinity  of  the  blood  is  reduced,5  but  the  methods 
available  for  determining  blood  alkalinity  are  too  unreliable  to 
decide  this  point  satisfactorily.6  Brandenburg7  states  that  the 
nondiffusible  alkali  varies  according  to  the  amount  of  proteid  in 
the  blood ;  in  pneumonia  and  acute  nephritis  he  found  it  low. 
Rzentkowski 8  also  attributes  the  reduced  power  of  the  blood 
to  neutralize  acids,  which  he  observed  in  acute  infectious  diseases 
and  in  uremia,  to  decreased  quantity  and  altered  quality  of  the 
blood  proteids.  Libman 9  has  suggested  that  the  acids  produced 
by  the  bacteria  themselves  may  be  a  factor  in  reducing  the 
alkalinity  of  the  blood  in  infection.  Orlowsky 10  could  find  no 

1  Pniiger's  Arch.,  1900  (81),  535. 

2  For  bibliography  on  Alkalinity  of  Blood  see  v.  Limbeck,  "  Klinische 
Pathol.  des  Blutes,"  1896 ;  and  Hamburger,  "  Osmotischer  Druck  und  lonen- 
lehre,"  1902. 

3  See  Hamburger,  he.  tit,  p.  280. 

4  Arch.  f.  Entwicklungsmechanik,  1898  (7),  631. 

5  See  v.  Limbeck,  loc.  tit.;  see  also  Orlowsky,  Deut.  med.  Woch.,  1903  (29), 
601. 

6  Kireeff  (Cent.  f.  inn.  Med.,  1905  (26),  473)  claims  that  in  most  febrile 
conditions  the  alkalinity  as  determined  by  titration  is  normal  or  slightly  lowered, 
except  in  typhus  (Flecktyphus),  in  which  he  finds  it  always  increased. 

7  Deut.  med.  Woch.,  1902  (28),  78  ;  Zeit.  f.  klin.  Med.,  1902  (45),  157. 

8  Arch.  exp.  Path.  u.  Pharm.,  1906  (55),  47. 
*  Jour.  Med.  Research,  1901  (6),  84. 

10  Loc.  cit. 

16 


242  DISTURBANCES  OF  CIRCULATION 

decrease  in  the  alkalinity  of  the  blood  in  leucocytosis,  or  when 
virulent  bacteria  were  introduced  into  the  blood.  Awerbach  l 
claims  that  in  severe  high  fevers  the  bactericidal  effect  of  the 
blood  alkalinity  is  increased  (see  also  "  Passive  Congestion " 
for  further  discussion  concerning  the  relation  of  alkalinity  to 
bactericidal  power). 

HEMORRHAGE 

Hemorrhages  result  from  an  altered  condition  in  the  vessel- 
walls,  which  may  be  due  either  to  trauma  or  to  chemical  inju- 
ries. Of  the  chemical  agencies  causing  hemorrhages,  bacterial 
products  are  the  most  important  practically,  but  many  poisons, 
such  as  phosphorus,  formalin,  phytotoxins  (ricin,  abrin,  and 
crotin),  and  zootoxins  (snake  venoms)  cause  numerous  and 
abundant  hemorrhages.  Formerly,  the  tendency  was  to  ascribe 
hemorrhages  from  the  above  causes  to  mechanical  injury  of  the 
vessels  by  thrombi,  or  by  emboli  of  agglutinated  corpuscles,  but 
the  work  of  Flexner2  has  shown  that  venoms  cause  hemor- 
rhages by  injuring  the  capillary  walls,  so  that  actual  rents  are 
produced  by  the  intravascular  pressure,  and  it  seems  highly 
probable  that  hemorrhages  are  produced  by  other  chemical  sub- 
stances in  a  similar  way.  We  may,  therefore,  refer  such  hem- 
orrhages to  an  endotheliotoxic  action  of  the  poison,  or  to  a  solvent 
effect  upon  the  intercellular  cement  substance.  In  the  case  of 
ordinary  chemical  poisons  the  endotheliotoxic  action  is  not  spe- 
cific, but  with  some  of  the  toxins  it  seems  to  be  quite  so ;  for 
example,  rattlesnake  venom  contains  an  endotheliotoxic  sub- 
stance (hemorrhagiTi),  which  seems  to  be  a  specific  poison  for 
endothelium,  and  which  is  the  most  dangerous  constituent  of 
the  venom.  If  we  immunize  animals  against  tissues  containing 
much  endothelium  (e.  g.y  lymph-glands),  their  serum  wrill  be 
found  to  contain  endotheliotoxins,  so  that  when  this  serum  is 
injected  subcutaneously  into  a  susceptible  animal,  large  local 
hemorrhages  result ;  if  injected  into  the  peritoneal  cavity,  there 
results  marked  desquamation  of  the  endothelial  cells,  which  soon 
undergo  degenerative  changes  (Ricketts 3 ).  It  is  quite  probable 
that  the  bacterial  poisons  that  cause  marked  hemorrhagic  mani- 
festations likewise  contain  endotheliotoxins,  although  this  matter 
does  not  seem  to  have  been  investigated. 

Even  hemorrhage  by  diapedesis  seems  to  be  due  to,  or  at  least 
associated  with,  chemical  changes  in  the  capillary  walls,  for 

1  Med.  Obosrenije,  1903,  p.  596. 

2 Univ.  of  Penn.  Med.  Bull.,  1902  (15),  355. 

'Trans.  Chicago  Path.  Soc.,  1902  (5),  181. 


HEMORRHAGE  243 

Arnold l  found  that  when  capillaries  from  which  diapedesis  had 
occurred  were  stained  by  silver  nitrate,  dark  areas  were  found 
between  the  endothelial  cells.  As  silver  nitrate  is  a  stain  for 
chlorides,  and  darkens  intercellular  substance  because  it  is  rich 
in  sodium  chloride  (Macallum),  it  is  probable  that  there  is  an 
increase  in  the  amount  or  a  difference  in  the  method  of  combina- 
tion of  the  chlorides  of  the  cement  substance  between  the  endo- 
thelial cells,  at  the  places  where  red  corpuscles  escape. 

Hemorrhage  in  cachectic  conditions  is  often  ascribed  to 
changes  in  the  vessel- walls  due  to  malnutrition,  but  it  is  diffi- 
cult to  imagine  capillary  walls  suffering  from  lack  of  nourish- 
ment, even  with  the  poorest  of  blood,  and  it  seems  more  probable 
that  the  hemorrhages  are  due,  even  in  cachexia,  to  chemical 
constituents  of  the  blood  that  injure  the  endothelium. 

Changes  in  the  Extravasated  Blood. — These  begin 
soon  after  its  escape.  In  most  situations  sufficient  fibrin  fer- 
ment is  formed  to  lead  to  prompt  clotting,  but  in  the  pleura 
and  other  serous  cavities  the  blood  may  remain  fluid  for  some 
time,  probably  because  of  lack  of  cellular  injury  that  might 
cause  liberation  of  fibrin  ferment.  If  the  blood  does  not  be- 
come infected,  the  rapidity  of  subsequent  changes  depends  chiefly 
upon  the  location  and  amount  of  blood.  Small  extravasations 
of  blood  into  the  tissues  are  subjected  to  the  action  of  the  tissue 
cells  and  of  leucocytes  emigrating  freely  from  the  capillaries ; 
large  masses  of  blood  are  but  little  affected  by  these  agencies, 
the  leucocytes  within  the  mass  soon  die,  and  secondary  changes 
go  on  very  slowly.  In  small  subcutaneous  hemorrhages  (e.  g., 
a  bruise)  enzymes  from  the  invading  leucocytes  and  tissue-cells 
soon  dissolve  the  small  quantities  of  fibrin  present ;  even  earlier 
the  stroma  of  the  red  corpuscles  is  so  altered  that  hemolysis 
occurs  and  the  hemoglobin  escapes  and  diffuses  into  the  tissues. 
This  hemolysis  may  be  brought  about  by  the  action  of  proteo- 
lytic  enzymes  on  the  corpuscles,  or  by  the  hemolytic  action  of  the 
products  ofproteid  splitting,  Soon  the  hemoglobin  disinte- 
grates, forming  the  masses  of  pigment  so  characteristic  of  old 
hemorrhagic  areas,  and  also  giving  rise  to  the  discoloration  ob- 
served beneath  the  skin  in  the  later  stages  of  resorption  of 
hemorrhagic  extravasations.  The  first  products  of  the  splitting 
of  hemoglobin  are:  (1)  The  proteid,  globin,  which  constitutes 
94  per  cent,  of  the  hemoglobin;  and  (2)  the  iron-containing 
coloring-matter,  hematin  (in  the  absence  of  oxygen  the  pigment 
is  reduced  hematin  or  hemochromogeri).  As  hematin  may  be 
experimentally  obtained  by  the  action  of  proteases  upon  hemo- 
1  Virchow's  Arch.,  1875  (62),  157. 


244  DISTURBANCES  OF  CIRCULATION 

globin,  the  decomposition  of  the  hemoglobin  in  the  tissues  is 
probably  accomplished  in  a  similar  way  by  the  proteases  of  the 
leucocytes,  tissue-cells  and  blood  plasma  ;  the  globin  is  thus 
digested  away  and  the  soluble  products  carried  off,  while  the 
insoluble  hematin  remains.1  The  hematin  gradually  undergoes 
further  changes,  forming  an  iron-free  pigment  (hematoidin)  and 
an  iron-containing  pigment  (hemosiderin). 

Hematoidin  is  nearly  or  quite  identical  with  the  bile-pig- 
ment, bitirubin,  and  is  absorbed  from  the  hemorrhagic  extrava- 
sation and  eliminated  as  bilirubin  in  the  bile.  Possibly  some 
of  the  hematoidin  undergoes  transformation  into  urobilin,  and 
is  then  eliminated  in  the  urine,  Hemosiderin  seems  to  be  rela- 
tively insoluble  and,  therefore,  is  more  slowly  removed,  so  that 
it  may  be  found  at  the  site  of  a  hemorrhage  after  the  other 
evidences  of  blood  extravasation  have  been  removed.  It  may 
be  easily  demonstrated  by  staining  with  potassium  ferrocyanide, 
the  Prussian  blue  that  is  formed  being  readily  distinguished. 
Unstained  hemosiderin  generally  appears  in  the  form  of  brown 
or  yellowish-brown  granules,  never  as  crystals.  After  a  time 
the  hemosiderin  is  taken  away,  and  probably  is  to  a  greater  or 
less  extent  deposited  in  the  liver  and  spleen,  either  as  hemo- 
siderin or  as  some  other  iron  compound.  Eventually  it  is  prob- 
ably utilized  to  make  new  hemoglobin  ;  at  any  rate,  the  iron 
liberated  by  the  breaking  up  of  hematin  within  the  body  does 
not  appear  to  be  eliminated.2 

The  changes  in  the  red  corpuscles  described  above  are  not  at 
all  peculiar  to  extravasated  blood,  but  are  quite  the  same  as 
the  changes  that  are  going  on  continuously  and  normally  in  the 
blood.  Red  corpuscles  are  short-lived,  being  but  non-nucleated 
fragments  of  cells,  and  they  are  continually  disintegrating  with 
the  production  of  iron-free  pigments  that  are  excreted  as  the 
coloring-matters  of  the  bile  and  the  urine,  while  the  iron  is 
worked  over  again  into  new  hemoglobin  after  a  varying  period 
of  storage  in  the  tissues,  particularly  in  the  spleen  and  liver. 
The  destruction  of  red  corpuscles  under  normal  conditions  seems 
to  take  place  chiefly  in  the  spleen,  bone-marrow,  and  hemolymph 
glands,  where  injured  or  decrepit  corpuscles  are  taken  out  of 
the  blood  by  the  phagocytic  endothelial  cells,  and  decomposed 
by  intracellular  enzymes.  In  hemorrhagic  extravasations  the 
changes  are  essentially  the  same ;  some  corpuscles  are  destroyed 
by  phagocytes,  but  more  by  extracellular  enzymes.  The  prod- 
ucts of  decomposition  also  seem  to  be  no  different  from  those 

1  More  fully  discussed  in  the  consideration  of  "  Pigmentation,"  Chap.  xvi. 
'See  Morishima,  Arch.  f.  exp.  Path.,  1898  (41),  291. 


HEMORRHAGE  245 

formed  during  normal  katabolism  of  hemoglobin,  and  they  meet 
the  same  fate  in  the  end. 

If  the  hemorrhages  are  very  abundant,  some  hemoglobin 
may  be  absorbed  as  such  and  appear  in  the  urine,  but  this  prob- 
ably seldom  happens  unless  red  corpuscles  are  also  being 
destroyed  in  the  circulating  blood.  An  increased  amount  of  iron 
accumulates  in  the  liver,  but  if  much  blood  has  been  lost  by 
hemorrhage  on  free  surfaces,  the  iron  content  of  the  liver  is 
decreased,  as  it  is  taken  away  to  form  new  hemoglobin  (Quincke ' ). 
Excretion  of  bile-pigments  is  increased  by  destruction  of  blood 
(Stadelmann),  but  not  greatly  in  the  case  of  hemorrhages,  for  the 
blood  is  decomposed  and  absorbed  too  slowly.  Schurig2  found 
that  hemoglobin  injected  into  the  tissues  is  partly  decomposed 
in  situ  with  formation  of  iron  compounds,  but  the  greater  part 
enters  the  circulation  as  hemoglobin,  and  is  partly  converted 
into  bile-pigment  by  the  liver-cells,  the  rest  being  converted  into 
iron  compounds  by  the  spleen,  bone-marrow,  and  renal  cortex. 

If  the  hemorrhagic  extravasation  has  been  large  in  amount, 
the  deeper  portions  of  the  mass  are  not  soon,  if  ever,  invaded 
by  leucocytes  or  tissue-cells.  Consequently  the  blood  is  acted 
upon  very  slowly  by  the  enzymes  liberated  by  the  leucocytes  it 
contains  itself,  and  by  the  small  amounts  of  proteases  in  the 
serum.  Furthermore,  the  products  of  decomposition  are  not 
soon  absorbed,  but  accumulate  in  considerable  amounts,  so  that 
we  often  find  crystalline  deposits  of  hematoidin,  sometimes 
even  of  hematin,  hemoglobin,  or  parahemoglobin  (Nencki  3 )  or 
methemoglobin. 

The  least  soluble  constituent  of  the  red  corpuscle  stroma, 
cholesterin,  also  accumulates  in  such  extravasations  as  large,  thin 
plates ;  after  most  of  the  other  products  of  disintegration  have 
been  absorbed  from  such  accumulations  of  blood,  the  most  con- 
spicuous part  of  the  residue  may  be  a  mass  of  cholesterin  crys- 
tals imbedded  in  proliferating  connective  tissue. 

HEMOPHILIA  * 

Since  hemophilia  seems,  superficially  at  least,  to  depend  upon 
some  alteration  in  a  chemical  property  of  the  blood,  namely, 
coagulability,  it  is  frequently  regarded  as  an  example  of  heredi- 
tary transmission  of  a  chemical  peculiarity.  The  exact  cause 

1  Deut.  Arch.  klin.  Med.,  1880  (25),  567;  1880  (27),  193. 

2  Arch.  exp.  Path.  u.  Pharm.,  1898  (41),  29. 


3  Arch.  exp.  Path.  u.  Pharm.,  1886  (20),  332. 
*  Literature  and  resume  given  by  Stempel,  Cent.  f.  Grenzgeb.  Med.  u.  Chir., 
1900  (3),  753 ;  Sahli,  Zeit.  f.  klin.  Med.,  1905  (56),  294. 


246  DISTURBANCES  OF  CIRCULATION 

of  this  peculiar  tendency  to  prolonged  bleeding  from  insignificant 
or  perhaps  imperceptible  wounds  has  been  sought  vigorously  by 
both  histological  and  chemical  means,  but  as  yet  without  avail. 
Various  observers  have  described  abnormal  thinness,  or  increased 
cellularity  or  fatty  degeneration  of  the  vessel-walls,  but  the 
findings  have  been  far  too  inconstant  to  afford  a  satisfactory 
anatomical  explanation  of  all  the  features  of  hemophilia.  Like- 
wise increased  blood  pressure  can  be  ruled  out,  for  although  the 
left  heart  is  frequently  enlarged,  there  is  usually  no  increased 
blood  pressure  demonstrable  ;  furthermore,  conditions  of  high 
blood  pressure,  such  as  nephritis,  do  not  cause  hemophilia.  The 
theory  of  "  hydremic  plethora  "  is  also  without  good  foundation. 

The  most  natural  place  to  look  for  the  fundamental  fault  is 
in  the  blood,  but  speaking  strongly  against  this  is  the  frequent 
occurrence  of  "  local  "  hemophilia  ;  e.  g.,  in  this  type  of  hemo- 
philia wounds  of  the  skin  may  behave  as  in  normal  individuals, 
whereas  any  injury  of  the  mucous  surfaces  is  followed  by  pro- 
nounced hemophilic  bleeding ; l  in  other  cases  the  hemophilic 
bleeding  is  limited  to  regions  above  the  shoulders ;  in  still 
another  class  the  bleeding  is  always  from  one  organ,  e.  g.,  the 
kidneys.  Nevertheless,  a  great  deal  of  investigation  of  the  blood 
has  been  done,  chiefly  with  negative  results.  There  are  no 
characteristic  changes  in  the  cellular  elements  of  the  blood, 
beyond  the  changes  common  to  all  secondary  anemias,  except- 
ing possibly  a  decrease  in  the  number  of  white  corpuscles  with 
a  relative  increase  in  the  number  of  lymphocytes  as  observed  by 
Sahli.  No  constant  alterations  in  the  salts  of  the  blood  have 
been  found  ;  and  the  proportion  of  water,  the  alkalinity,  and  the 
osmotic  pressure  of  the  serum  all  seem  to  be  normal.  Since 
bleeding  is  normally  stopped  principally  by  coagulation,  a 
deficiency  in  fibrin  or  its  antecedents  might  be  expected,  but 
most  studies  on  this  point  have  shown  a  normal  amount  of 
fibrinogen  in  the  blood  of  hemophilics,  the  frequent  formation  of 
large  tumors  of  clotted  blood  at  the  bleeding  points  supporting 
the  experimental  evidence  that  the  blood  contains  an  abundance 
of  fibrinogen.  As  to  the  rate  of  clotting,  the  results  obtained 
by  different  observers  are  by  no  means  in  accord,  which  seems 
to  be  explained  by  the  recent  studies  of  Sahli, 2  who  has  avoided 
a  number  of  errors  made  in  earlier  investigations.  He  found 
that  in  the  intervals  between  the  attacks  of  hemorrhage  the  rate 
of  the  coagulation  of  the  blood  is  constantly  much  slower  than 
normal.  During  an  attack  of  bleeding  the  coagulation  time 
approaches  the  normal ;  indeed,  it  may  be  faster  than  normal ; 

1  Abderhalden,  Ziegler's  Beitr.,  1904  (35),  213.  2  Loc.  tit. 


HEMOPHILIA  247 

apparently  this  is  due  to  a  reaction  on  the  part  of  the  organism 
to  the  loss  of  blood.  If  blood  is  collected  directly  from  the 
site  of  bleeding  the  coagulation  time  is  very  rapid,  because  of 
the  accumulation  of  fibrin  ferment  from  the  clot  over  which  the 
escaping  blood  flows.  Yet  in  spite  of  the  normal  coagulability 
of  the  blood  and  the  rapid  clotting  after  the  blood  escapes  from 
the  vessel,  bleeding  continues  for  long  periods  before  it  can  be 
stopped.  As  there  is  no  general  change  in  the  properties  of  the 
blood  to  account  for  the  bleeding,  and  as  local  influences  seem 
to  be  important  in  hemophilia,  Sahli  advances  the  plausible 
hypothesis  that  chemical  changes  in  the  vessels  must  be  the 
essential  factor  in  hemophilia.  Hemorrhage  is  ordinarily 
checked  chiefly  by  the  formation  of  clots  that  plug  up  the  bleed- 
ing vessels  at  the  point  of  the  hemorrhage.  The  local  formation 
of  a  clot  is  believed  to  be  due  to  liberation  of  fibrin-ferment  (or 
its  antecedents)  by  the  injured  cells  of  the  vessel- wall  at  the 
point  of  the  vascular  lesion.  If  the  cells  of  the  vessel- wall  are 
deficient  in  these  fibrin-forming  substances,  the  blood  will  not 
clot  in  the  mouths  of  the  vessels,  but  will  first  clot  when  it 
reaches  a  place  where  fibrin-forming  substances  are  furnished  by 
other  tissues,  or,  as  is  generally  the  case,  when  the  leucocytes 
are  broken  up  by  exposure  to  the  air  or  other  injurious  influ- 
ences so  that  they  liberate  fibrin-ferment.  Under  these  condi- 
tions the  blood  may  clot  in  large  masses,  but  as  there  is  no 
fibrin  adhering  to  the  vessel-walls  at  the  bleeding  openings, 
blood  continues  to  escape.  Sahli  considers,  therefore,  that  the 
cause  of  hemophilia  lies  in  hereditary  deficiency  of  the  fibrin- 
forming  substances,  thrombokinase  or  zymoplastic  substance 
(  see  "  Thrombosis  "),  in  the  vessel- walls,  so  that  when  the  vessels 
are  injured  there  is  no  local  production  of  fibrin  such  as  occurs 
normally.  Local  hemophilia  may  be  explained  readily  as  a 
local  deficiency  in  fibrinoplastic  material.  In  general  hemo- 
philia even  the  leucocytes  may  exhibit  the  same  defect,  in  which 
case  clotting  of  the  blood  is  diminished  even  outside  the  tissues. 
This  hypothesis  seems  to  be  in  excellent  agreement  with  the 
facts  now  known,  but  there  yet  remains  to  be  demonstrated 
such  a  lack  of  fibrin-forming  elements  in  the  vessel-walls  and 
other  tissues  of  a  hemophilic  subject.  This  hypothesis  perhaps 
also  explains  why  the  marked  increase  in  coagulability  of 
the  blood  obtained  by  administration  of  calcium  salts  (Wright l ) 
is,  as  "Wright's  observations  show,  not  sufficient  alone  to  stop 
hemophilic  bleeding,  even  though  the  rapidity  of  clotting  is 
much  greater  than  normal. 

1  Brit.  Med.  Jour.,  1894  (ii),  57. 


248  DISEASES  OF  THE  BLOOD 

ANEMIA  AND  THE  SPECIFIC  ANEMIAS 

The  customary  division  of  the  anemias  is  into — (a)  primary, 
i.  e.,  those  in  which  the  cause  seems  to  depend  upon  some  abnor- 
mality in  the  blood-forming  organs  or  in  the  blood  itself;  and 
(6)  secondary,  embracing  anemias  the  result  of  some  obvious 
cause,  such  as  hemorrhage,  poisoning  with  blood-destroying 
poisons,  cachexia,  etc.  In  these  various  forms  of  anemia 
certain  chemical  differences  prevail,  but  they  are  by  no  means 
so  striking  as  are  the  histological  differences  in  the  formed 
elements  of  the  blood.1 

SECONDARY    ANEMIAS 

As  the  simplest  variety,  anemia  following  a  single  large 
hemorrhage  may  be  considered  first. 

If  loss  of  blood  by  hemorrhage  is  rapid,  the  effects  are  natu- 
rally much  more  serious  than  when  the  loss  is  slow.  The  total 
quantity  of  blood  in  the  average  adult  is  estimated  at  about  -^ 
to  -^j  the  total  body  weight  (therefore  about  10  to  12  pounds), 
although  this  proportion  does  not  hold  for  extremely  obese  or 
extremely  thin  individuals  ;2  in  infants  the  proportion  is  lower — 
about  2^5-.  When  one-third  of  the  total  amount  of  blood  is  lost 
rapidly,  a  marked  fall  of  blood  pressure  occurs ;  loss  of  one- 
half  of  the  total  amount  may  be  fatal,  and  loss  of  more  than  that 
at  one  time  usually  is  fatal.  The  chief  cause  of  death  following 
large  hemorrhages  is  the  low  blood  pressure  rather  than  the  loss 
of  any  of  the  constituents  of  the  blood ;  hence  the  successful 
results  of  the  use  of  physiological  salt  solution  after  severe  hemor- 
rhage. The  number  of  corpuscles  may  be  greatly  reduced  after 
several  small  hemorrhages,  even  to  as  low  as  1 1  per  cent,  of  the 
normal  number  (Hayem),  without  fatal  results,  because  in  the 
intervals  between  the  hemorrhages  enough  fluid  has  been  taken 
up  by  the  blood  to  maintain  the  blood  pressure  within  safe  limits. 

After  a  severe  hemorrhage  the  composition  of  the  blood 
changes  rapidly,  for  the  fluids  contained  within  the  tissues  and 
lymph-spaces  pass  into  the  blood  in  large  amounts.  This  helps 
to  maintain  blood  pressure,  but  results  in  the  blood  containing 
a  larger  proportion  of  water  and  salts  and  a  smaller  amount  of 
proteid  and  red  corpuscles ;  the  "  total  alkalinity "  also  falls, 
largely  because  of  the  scarcity  of  "  fixed  alkali,"  on  account  of 
the  poverty  in  corpuscles  and  blood  proteids.  The  proportion 
of  water  increases  at  first  more  rapidly  than  the  proportion  of 

1  Concerning  Iqcal  anemia,  see  "  Infarcts." 

2  Haldane  and  Smith  (Jour,  of  Physiol.,  1900  (25),  331)  estimate  the  blood 
of  adults  at  but  -^  of  the  body  weight. 


SECONDARY  ANEMIA  249 

salts,  and  as  a  consequence  the  size  of  the  red  corpuscles  is 
increased  because  of  imbibition  of  water;  indeed,  it  is  possible 
that  this  may  even  be  sufficient  to  cause  hemolysis,  which  will 
happen  if  the  isotonic  strength  of  the  blood  becomes  less  than 
that  of  a  0.46  per  cent.  NaCl  solution  (Limbeck),  while  swelling 
may  occur  whenever  the  strength  is  below  0.8  per  cent. 

Regeneration  of  the  blood  begins  very  soon,  and  for  some 
time  the  number  of  corpuscles  exceeds  the  proportion  of  hemo- 
globin. During  this  time  the  amount  of  iron  in  the  liver  and 
spleen  is  decreased,  it  being  taken  up  to  be  used  in  the  formation 
of  new  hemoglobin.  If  the  hemorrhages  are  numerous  and  the 
condition  of  anemia  prolonged,  secondary  changes  in  the  viscera 
may  occur,  fatty  metamorphosis  being  most  marked,  supposedly 
because  of  decreased  oxidation.  Indeed,  many  observers  state  that 
repeated  bleedings  greatly  increase  body  weight  by  causing 
increased  fat  deposition. 

Metabolic  Changes. — Gies1  studied  the  metabolism  of 
dogs  after  withdrawing  a  total  amount  of  blood  equal  to  11.5 
per  cent,  of  the  body  weight  during  four  bleedings,  and  found 
that  a  slight  and  temporary  increase  in  nitrogenous  elimination 
followed  the  bleedings,  owing  to  an  increased  proteid  katab- 
olism.  Sugar  increases  in  the  blood,  while  albumin  and  lactic 
acid  appear  in  the  urine.  After  each  successive  hemorrhage  the 
proportion  of  fibrin  and  the  coagulability  of  the  blood  increase, 
while  the  proportion  of  the  ash  obtained  from  both  blood  and 
serum  remains  practically  unchanged  (Meyer  and  Gies).  Bau- 
mann 2  states  that  in  regeneration  after  hemorrhage  the  serum 
albumins  increase  more  rapidly  than  the  globulins,  while  others 
have  observed  the  opposite  relation.  The  urine  in  secondary 
anemia  shows  the  effects  of  increased  proteid  katabolism,  its 
specific  gravity,  total  solids,  and  total  nitrogen  being  raised  ;  the 
total  amount  of  urine  is  at  first  diminished  because  of  lowered 
blood  pressure,  but  it  soon  rises  above  normal  and  later  falls 
back  to  normal.  The  view  formerly  held  that  oxidation  is 
decreased  in  anemia  has  been  considerably  modified  by  more 
recent  investigations.3 

Secondary  anemia  due  to  cachexia,  or  to  malnutrition, 
is  accompanied  by  a  general  decrease  in  all  the  elements  of  the 
blood,  both  cellular  and  chemical.  The  proteids  of  the  plasma, 
particularly,  show  a  decrease  in  starvation,  being  drawn  on  by 
the  cells  for  food,  and  the  total  quantity  of  blood  as  well  as  of 

1  American  Med.,  1904  (8),  155  (  resume*  of  literature). 

2  Jour,  of  Physiol.,  1903  (29),  18. 

3  See  Mohr,  Zeit.  exp.  Path.,  1906  (2),  435. 


250  DISEASES  OF  THE  BLOOD 

each  of  its  constituents  is  decreased  (Panum l ),  but  the  propor- 
tion of  blood  to  body  weight  remains  about  normal. 

Anemia  due  to  hemolytic  agencies  presents  quite  differ- 
ent features,  in  that  the  red  corpuscles  are  almost  solely  attacked 
and  the  products  of  their  disintegration  are  present  in  the  plasma. 
As  a  result,  the  plasma  or  serum  may  contain  free  hemoglobin, 
and  if  the  hemoglobin  is  in  large  amounts,  it  may  escape  into 
the  urine.  Thus  paroxysmal  hemoglobinuria  is  probably  due  to 
the  presence  in  the  blood  of  hemolytic  substances,  which  can  be 
demonstrated  in  the  blood  of  the  patients  during  the  attack.2 
The  products  of  the  decomposition  of  the  hemoglobin  set  free 
by  hemolysis  are  present  not  only  in  the  blood,  but  also  in  the 
organs,  particularly  the  liver  and  spleen,  which  become  rich  in 
iron.  Excretion  of  bile-pigments  also  increases,  and  "  hematog- 
enous  jaundice  "  may  result,  the  bile-pigments  that  are  present 
in  the  blood  being  derived  from  the  hematoidin  of  the  hemo- 
globin molecule.  Changes  in  metabolism  occur  which  are  quite 
similar  to  those  observed  in  other  forms  of  anemia,  with  fatty 
changes  in  all  the  parenchymatous  organs,  increased  proteid 
katabolism,  and  an  excessive  quantity  of  pigmentary  substances, 
particularly  urobilin,  in  the  urine. 

CHLOROSIS 

The  characteristic  feature  of  the  blood  in  chlorosis  is  the 
relatively  small  amount  of  hemoglobin  in  proportion  to  the 
number  of  corpuscles.  Apparently,  therefore,  the  fault  lies 
rather  in  the  manufacture  of  hemoglobin  than  in  either  a 
destruction  or  a  deficient  formation  of  red  corpuscles.  Erben's 3 
analyses  of  chlorotic  blood  showed  that  the  total  amount  of 
proteid  is  decreased,  chiefly  because  of  the  deficiency  of  hemo- 
globin ;  the  relation  of  serum  globulins  and  serum  albumins  is 
unchanged,  while  the  proportion  of  fibrinogen  is  increased. 
There  is  much  more  fatty  substance  than  normal  in  both  the 
serum  and  the  erythrocytes,  but  the  lecithin  is  decreased  both 
in  the  serum  and  in  the  total  blood,  although  somewhat 
increased  in  the  red  cells.  Cholesterin  is  decreased  in  both 
serum  and  corpuscles.  In  the  ash,  phosphoric  acid,  potas- 
sium, and  iron  are  decreased,  while  calcium  and  magnesium  are 
both  increased.  An  apparent  increase  in  sodium  chloride  exists, 
but  it  is  only  apparent,  being  the  result  of  the  increase  in  the 
proportion  of  plasma  in  the  blood. 

1  Virchow's  Arch.,  1864  (29),  241. 

2  See  Donath  and  Landsteiner,  Zeit.  klin.  Med.,  1905  (58),  173 ;  Eason, 
Jour.  Pathol.  and  Bact.,  1906  (11),  203. 

3  Zeit.  klin.  Med.,  1902  (47),  302. 


CHLOROSIS  251 

The  decrease  in  hemoglobin  is  demonstrable  chemically  as 
well  as  microscopically,  Becquerel  and  Rodier1  having  found 
the  amount  of  iron  in  the  total  blood  decreased  in  direct  pro- 
portion to  the  apparent  decrease  in  hemoglobin,  which  frequently 
falls  to  30-40  per  cent.,  and  may  drop  to  20  per  cent,  or  possibly 
less.  Alkalinity,  as  determined  by  titration,  is  diminished  in 
some  cases,  but  generally  remains  nearly  normal.  The  cor- 
puscles are  said  to  contain  a  larger  proportion  of  water  than 
normal,  independent  of  the  proportion  of  water  present  in  the 
serum.  Limbeck  found  their  isotonitity  (i.  e.,  the  strength  of 
NaCl  necessary  to  prevent  hemolysis)  very  low — about  0.38—0.4 
per  cent.  NaCl. 

Very  few  changes  seem  to  occur  in  the  organs  of  the  body ; 
the  usual  tendency  to  lay  on  fat,  and  the  occurrence  of  fatty 
degeneration  observed  commonly  in  anemias,  may  be  exhibited, 
and  are  correlated  with  Erben's  observation  of  an  increased  fat 
content  in  the  blood  ;  but  these  changes  are  often  absent.  The 
hypoplasia  of  the  aorta,  upon  which  Virchow  laid  so  much 
stress,  is  now  considered  to  be  of  little  or  no  significance. 
Thrombosis  is  a  not  infrequent  complication  of  chlorosis,2  and 
is  probably  favored  by  the  increased  fibrin-content  of  the  blood 
and  the  tendency  to  fatty  changes  in  the  vessel-walls. 

Studies  of  nitrogenous  metabolism  by  Vannini 3  showed  practi- 
cally no  alterations  except  a  slight  retention  of  nitrogen. 

Etiology. — As  to  the  etiology  of  chlorosis,  chemical  find- 
ings indicate  some  possibilities  and  negative  others,  but  decide 
nothing.  That  chlorosis  does  not  depend  upon  a  hemolytic  poi- 
son is  well  established  by  the  following  facts  :  there  is  no  free 
hemoglobin  in  the  blood  plasma,  and  even  less  iron  in  the  serum 
ash  than  normal ;  lecithin  and  cholesterin,  important  products 
of  disintegration  of  erythrocytes,  are  both  decreased  in  the 
serum ;  hematogenous  icterus  does  not  occur,  and  the  amount 
of  pigments  in  the  urine  and  feces  is  decreased. 

Apparently,  therefore,  hematogenesis  is  at  fault,  particularly 
the  formation  of  hemoglobin,  since  this  is  more  deficient  than  is 
the  total  number  of  red  corpuscles.  The  rapid  improvement 
in  the  condition  that  follows  the  administration  of  iron  would 
seem  to  indicate  that  a  deficient  supply  of  iron  is  the  cause  of 
chlorosis,  but  numerous  objections  exist  to  this  hypothesis. 

^or  literature  see  Krehl,  "  Pathologische  Physiologic,"  1904,  p.  137; 
Swing,  "  Clinical  Pathology  of  the  Blood,"  1901,  p.  167;  Kossler,  Cent.  f.  inn. 
Med.,  1897  (18),  657. 

2  See  Schweitzer,  Virchow's  Arch.,  1898    (152),  337,  and   Leichtenstern, 
Munch,  med.  Woch.,  1899  (46),  1603. 

3  Virchow's  Arch.,  1904  (176),  375. 


252  DISEASES  OF  THE  BLOOD 

Bunge  advanced  the  idea  that  under  normal  conditions  the  only 
form  of  iron  that  can  be  absorbed  is  that  which  is  combined 
with  proteids,  particularly  nucleoproteids ;  iron  administered  in 
inorganic  form,  or  as  compounds  with  organic  acids,  he  believed, 
can  all  be  recovered  from  the  feces,  and,  therefore,  is  not 
absorbed.  He  suggested  that  in  chlorosis  the  iron  taken  with 
the  ordinary  food  is  precipitated  in  the  intestines  by  sulphides 
or  other  products  of  intestinal  putrefaction,  and  hence  there 
results  a  deficiency  in  the  amount  of  iron  absorbed  and  avail- 
able for  the  manufacture  of  hemoglobin.  The  inorganic  iron 
given  in  chlorosis,  Bunge  believes,  owes  its  efficiency  to  its 
saturating  all  of  these  sulphides  so  that  the  nucleoproteid-iron 
is  not  precipitated,  and  can,  therefore,  be  absorbed.  Many 
objections  have  been  raised  to  Bunge' s  hypothesis,  however,  for 
competent  observers  have  failed  to  find  any  abnormal  putrefac- 
tion in  chlorosis,  and  others  have  found  that  sulphide  of  iron 
itself  gives  good  results  in  the  treatment  of  chlorosis,  while 
bismuth  and  other  sulphur-binding  substances  are  without 
effect.  Furthermore,  Bunge' s  contention  that  iron  administered 
in  medicinal  form  is  not  absorbed  seems  to  have  been  completely 
disproved  by  several  experimenters.1 

As  a  consequence  of  all  these  conflicting  data  we  are  at 
present  completely  in  the  dark  as  to  the  reason  for  that  failure 
to  properly  manufacture  hemoglobin  which  seems  to  be  at  the 
bottom  of  chlorosis.  The  hypothesis  that  iron  and  arsenic 
favor  recovery  by  stimulating  the  hemogenetic  tissues,  which  is 
urged  by  v.  Noorden  and  others,  is  unsatisfactory  in  the 
extreme,  and  explains  nothing.  There  is  absolutely  no  ques- 
tion that  administration  of  iron  restores  the  composition  of  the 
blood  to  normal,  usually  quite  rapidly,  and  this  seems  to  leave 
as  most  probable  the  explanation  that  in  some  way  an  iron 
starvation  is  the  fundamental  cause  of  chlorosis.  However,  as 
Ewing  says,  any  theory  must  be  inadequate  that  fails  to  take 
into  account  the  age  of  puberty,  the  female  sex,  and  the  func- 
tion of  menstruation. 

PERNICIOUS    ANEMIA 

In  contrast  to  chlorosis  many  evidences  of  hematolysis  may 
be  found  in  pernicious  anemia,  particularly  the  increased  amounts 
of  iron  in  the  liver,  spleen,  and  kidneys ;  hemoglobinemia  and 
hemoglobinuria ;  increase  in  urobilin,  and  not  infrequently  icterus. 

1  Full  review  with  bibliography  by  Abderhalden  in  his  "  Lehrbuch  der 
physiol.  Chemie,"  1906,  pp.  408-430.  For  literature  on  treatment  of  chlorosis  see 
Komberg,  Berl.  klin.  Woch.,  1897  (34),  533. 


PERNICIOUS  ANEMIA  253 

Chemical  Changes. — Erben's1  analyses  of  the  blood  in  pernicious 
aueinia  gave  the  following  results :  The  proteids  are  decreased,  both  in 
the  serum  and  in  the  blood  as  a  whole  ;  particularly  .in  the  latter,  because 
of  the  great  decrease  in  the  number  of  corpuscles.  The  quantity  of  pro- 
teids in  the  individual  corpuscles  is  increased,  corresponding  to  their 
increased  size.  Fibrin  is  decreased  in  total  amount,  but  relatively 
normal  as  compared  with  the  total  proteids  ;  albumin  is  normal ;  serum 
globulin  much  decreased.  The  proportion  of  water  is  much  increased, 
both  in  the  serum  and  in  the  corpuscles.  Fat  is  present  in  normal 
amounts ;  cholesterin  is  decreased,  although  in  relatively  normal 
quantities  in  the  corpuscles.  Lecithin  is  decreased  in  the  total  blood, 
but  increased  proportionately  in  the  corpuscles.  The  total  ash  is 
increased,  owing  chiefly  to  an  excessively  large  proportion  of  NaCl 
and  a  slight  increase  in  calcium  and  magnesium  ;  potassium  and  phos- 
phoric acid  are  decreased  because  of  the  small  number  of  corpuscles  ; 
but  the  serum  itself  contains  more  P2O5  and  potassium  than  normal. 
Although  the  total  iron  is,  of  course,  much  decreased,  there  is  iron  in  the 
serum  (indicating  hemolysis)  and  the  proportion  of  iron  in  the  cor- 
puscles is  increased  ;  but  as  the  amount  of  iron  in  the  corpuscles  is  even 
greater  than  corresponds  to  the  hemoglobin  increase,  it  would  seem  that 
either  the  hemoglobin  in  pernicious  anemia  is  very  rich  in  iron,  or  that 
'the  corpuscles  contain  iron  bound  in  some  form  other  than  hemoglobin. 

The  analyses  of  Rumpf  2  agree  quite  closely  with  those  of  Erben,  and, 
taken  jointly  with  other  analyses  in  the  literature,  show  the  large  pro- 
portion of  water  in  the  blood,  the  small  amount  of  solids,  the  large 
amount  of  NaCl,  and  the  decrease  in  potassium  and  iron.  Eumpf  also 
examined  the  brain,  liver,  heart,  and  spleen  in  one  case.  Water  was  found 
increased  in  the  heart,  decreased  in  the  other  organs,  the  solids  not  being 
decreased  in  any  of  the  organs.  There  was  little  fat  in  any  of  the  organs  or 
in  the  blood,  but  NaCl  was  generally  increased.  The  liver  contained  four 
or  five  times  as  much  iron  as  normal;  the  spleen  three  or  four  times. 
Eumpf  is  inclined  to  lay  great  stress  on  the  general  poverty  of  the  body 
in  potassium,  and  suggests  its  therapeutic  application.  Syllaba  3  found 
bilirubin  and  also  free  hemoglobin  in  the  blood  of  seven  patients. 
Schumm  4  could  find  no  proteoses  or  other  evidences  of  proteid  decom- 
position in  the  blood  in  a  case  of  pernicious  anemia. 

v.  Jaksch  and  also  v.  Limbeck  5  have  found  some  decrease  in  total 
alkalinity,  which  probably  depends  on  the  loss  of  proteids  and  their 
fixed  alkali. 6  The  red  corpuscles  are  very  susceptible  to  hemolysis  by 
lowering  of  osmotic  pressure  ("  high  isotonicity, "  equal  to  0. 54  per  cent. 
NaCl — v.  Limbeck).  The  specific  gravity  of  the  whole  blood  is,  of 
course,  decreased,  being  sometimes  even  lower  than  that  of  normal  serum. 

In  six  cases  of  pernicious  anemia  Stuhlen7  found  abundant  iron  in 
the  liver  and  spleen  microscopically,  and  less  constantly  in  the  kidneys 
and  bone-marrow.  Hunter  8  gives  the  following  results  of  analysis  of  the 
liver,  kidney,  and  spleen  for  iron  : 

1  Zeit.  klin.  Med.,  1900  (40),  266. 

2  Berl.  klin.  Woch.,  1901  (38),  477. 

8  Abst.  in  Folia  Hematol.,  1904  (1),  283  and  589. 
*  Hofmeister's  Beitr.,  1903  (4),  453. 

5  "  Klin.  Pathol.  des  Blutes,"  Jena,  1896,  p.  311. 

6  See  Brandenburg,  Zeit.  klin.  Med.,  1902  (45),  157. 

7  Deut.  Arch.  klin.  Med.,  1895  (54),  248  (literature). 

8  Lancet,  1903  (i),  283. 


254  DISEASES  OF  THE  BLOOD 

Liver  and  0  -,nn, 

kidney.  Spleen. 

Pernicious  anemia,  seven  cases  average  .    .    .    .  0.360  per  cent.    0.125  per  cent. 
Other  conditions  (with  anemia),  average    .    .    .  0.079        "         0.362      " 

Healthy  organs 0.084        "         0.090       " 

Iron  is  also  found  in  the  hemolymph  glands,  sometimes  more  abundantly  than 
in  the  spleen  ( Warthin l ). 

Extensive  studies  on  the  proteid  metabolism  of  pernicious  anemia  by 
Rosenquist 2  showed  that  there  is  a  considerable  destruction  of  tissue 
proteids,  as  indicated  by  nitrogen  loss,  but  that  at  times  nitrogen  may  be 
stored  up  for  brief  periods.  At  times  there  may  also  be  an  excessive 
elimination  of  purin  nitrogen,  indicating  destruction  of  nuclear  elements. 
In  anemia  due  to  Bothriocephalus  quite  similar  changes  were  observed. 

Hunter 3  describes  the  condition  of  the  urine  in  pernicious  anemia, 
particularly  with  reference  to  the  elimination  of  much  ' '  pathological 
urobilin,"4  which  seems  to  be  produced  by  intracellular  destruction  of 
hemoglobin.  Iron  also  appears  in  the  urine  in  considerable  quantities. 

Summary. — Putting  together  the  above  findings,  we  see  that 
in  pernicious  anemia  we  have  every  evidence  that  excessive 
hemolysis  is  taking  place,  and  the  fact  that  continued  poisoning 
by  toluylendiamin 5  and  other  hemolytic  poisons,  such  as  that 
of  Bothriocephalus  y  may  give  rise  to  a  condition  resembling 
pernicious  anemia  very  closely,  indicates  strongly  that  hemo- 
lytic poisons  are  the  cause  of  pernicious  anemia.  Histological 
studies  show  the  same  thing,  and,  as  Warthin  6  says  :  "  The 
hemolysis  of  pernicious  anemia  does  not  differ  in  kind  from  that 
occurring  normally  or  in  certain  diseased  conditions  ;  the  dif- 
ference is  one  of  degree  only."  The  hemolysis  seems  to  go  on 
chiefly  inside  of  phagocytic  cells  instead  of  in  the  blood,  prob- 
ably because  the  phagocytes  pick  up  the  corpuscles  as  soon  as 
they  have  been  injured  by  the  hemolytic  poisons.  The  origin 
and  the  nature  of  these  hypothetical  poisons  have  been  sought 
in  vain.  Some  authors  have  referred  them  to  infections  of 
unknown  nature,  occurring  perhaps  in  the  mouth  and  gastro- 
intestinal tract  (Hunter 7  ),  or  to  hemolytic  products  of  intestinal 
putrefaction,8  or  to  faulty  metabolism.  Many  others,  with 

1  Amer.  Jour.  Med.  Sci.,  1902  (124),  674. 

2  Zeit.  klin.  Med.,  1903  (49),  193  (literature.) 

3  British  Med.  Jour.,  1890  (ii),  1  and  81. 

4  See  also  Mott,  Lancet,  1890  (i),  287;  and  Syllaba,  Abst.  in  Folia  Hema- 
tol.,  1904  (1),  283. 

5  Syllaba,  Hunter  (loc.  cit.}. 

6  Loc.  cit.  »  Lancet,  1903  (1),  283. 

8  See  Kiilbs  (Arch.  exp.  Path.  u.  Pharm.,  1906  (55),  73),  who  found  the 
intestinal  contents  of  patients  with  chronic  intestinal  disorders  to  contain 
hemolytic  substances  of  undetermined  character. 

Herter  (Jour.  Biol.  Chem.,  1906  (2),  1)  suggests  a  relation  between  intes- 
tinal infection  with  B.  aerogenes  capsulatusy  which  produces  hemolytic  sub- 
stances, and  pernicious  anemia. 


LEUKEMIA  255 

perhaps  the  best  of  grounds,  would  ascribe  pernicious  anemia  to 
a  multiplicity  of  causes,  which  produce  a  protracted  slight  hem- 
olysis  that  continues  until  the  hematogenetic  organs  give  out, 
their  exhaustion  being  perhaps  hastened  by  the  influence  of  the 
toxic  substances  in  the  blood ;  hematogenesis  then  becomes 
insufficient  to  replace  the  lost  corpuscles,  and  the  picture  of  per- 
nicious anemia  is  established.1 

LEUKEMIA 

In  leukemia  the  chemical  changes  in  the  red  corpuscles  take 
a  less  prominent  position,  resembling  either  those  of  a  secondary 
anemia  or  chlorosis,  while  the  enormous  number  of  leucocytes 
is  the  prominent  feature  and  causes  marked  alterations  in  the 
composition  of  the  blood.  Large  quantities  of  nucleoproteids 
and  also  of  the  intracellular  enzymes  are  introduced  into  the 
blood  by  the  excessive  leucocytes.  As  the  leucocytes  are 
constantly  breaking  down,  more  or  less  of  the  products  of  their 
decomposition  are  present  in  the  blood  and  appear  in  the  urine. 
Because  of  the  relatively  slight  metabolic  activity  of  the  lympho- 
cytes the  various  chemical  alterations  are  all  less  marked  in 
lymphatic  than  in  myelogenous  leukemia.2 

Chemistry  of  the  Blood. — Considering  the  quantitative  alterations 
in  the  constituents  of  the  blood,  we  find  the  specific  gravity  lowered, 
but  not  so  much  as  it  would  be  in  a  simple  anemia  with  equally  low 
hemoglobin,  for  the  loss  of  hemoglobin  is  partly  compensated  by  the 
increase  in  leucocytes  and  their  products.  The  serum  shows  but  slight 
change  in  specific  gravity,  a  slight  decrease  in  proteids  being  compensated 
by  an  increase  in  the  NaCl.  The  freezing-point  of  the  blood  is  lowered 
(Cohn 3 ),  which  is  probably  due  to  the  increase  in  crystalloidal  products 
of  cellular  decomposition.  Erben  4  found  that  in  lymphatic  leukemia 
the  serum  contains  less  cholesterin  than  normal,  although  the  fat 
content  may  be  rather  high.  Calcium  is  frequently  found  increased, 
probably  because  of  destruction  of  the  bone  tissue.  In  the  red  corpuscles 
the  proportion  of  iron  is  decreased  as  is  also  that  of  the  cholesterin,  that 
of  the  lecithin  being  somewhat  increased.  The  total  amount  of  potassium 
and  iron  in  the  blood  is  decreased,  but  the  P2O5  in  the  ash  is  increased 
because  of  the  large  amount  of  nucleoproteid  in  the  blood.  A  number 
of  the  earlier  writers  describe  a  decreased  alkalescence  which  probably 
is  due  to  the  deficiency  in  the  fixed  alkali  of  the  proteids.  Scherer  and 
others  have  reported  the  finding  of  lactic,  formic,  and  acetic  acids  in 
leukemic  blood. 

1  See  also  Bunting,  Johns  Hopkins  Hosp.  Bull.,  1905^(16),  222. 

2  Stern  and  Eppenstein  have  observed  that  the  striking  proteolytic  power 
of  the  leucocytes  from  the  blood  in  myelogenous  leukemia  is  not  shown  by 
the    leucocytes   in   lymphatic    leukemia  (Sitz.  d.   Schles.  Ges.  f.   vaterland. 
Cultur,  June  29,  1906). 

3  Mitteil.  aus  dem  Grenzgeb.  Med.  u.  Chir.,  1906  (15),  H.  1. 

4  Zeit.  klin.  Med.,  1900  (40),  282. 


256  DISEASES  OF  THE  BLOOD 

The  poor  coagulation  of  leukemic  blood  has  been  long  known, 
but  the  reason  for  it  has  not  yet  been  ascertained.  Some  investi- 
gators have  reported  a  deficiency  in  fibrin,  while  others  have 
found  it  increased.  More  recent  reports,  however,  indicate  that 
there  is  no  marked  change  in  either  the  amount  of  fibrinogen 
or  of  the  fibrin-ferments.  Erben  l  found  a  normal  amount  of 
fibrin  in  the  blood  in  lymphatic  leukemia  ;  and  in  three  cases  of 
myelogenous  and  one  of  lymphatic  leukemia,  Pfeiffer2  found 
the  amount  of  fibrinogen  nearly  normal.  This  is  quite  remark- 
able in  view  of  the  fact  that  in  ordinary  forms  of  leucocytosis 
both  the  amount  of  fibrinogen  and  the  rapidity  of  clotting  are 
increased.  It  is,  therefore,  extremely  difficult  to  understand 
the  poor  coagulability  of  leukemic  blood. 

Decomposition  Products. — Of  particular  interest  is  the 
finding  in  the  blood  of  decomposition  products  of  the  leucocytes, 
which  are  probably  produced  by  autolysis  of  the  leucocytes. 
Normal  leucocytes  are  rich  in  autolytic  enzymes,  which  under 
ordinary  circumstances  seem  to  be  held  in  check  by  the  anti- 
enzymes  of  the  blood.  In  leukemia  this  anti-enzyme  action 
seems  to  be  insufficient  to  prevent  leucocytic  autolysis,  for  even 
in  freshly  drawn  blood  proteoses  (or  at  least  non-coagulable 
proteids)  may  be  present.3  According  to  Erben,  this  is  true 
only  of  myelogenous  leukemia,  the  fresh  blood  in  lymphatic 
leukemia  not  only  being  free  from  non-coagulable  proteid,  but 
furthermore  this  product  of  proteolysis  does  not  soon  develop 
when  the  blood  is  kept  aseptically  at  incubator  temperature. 
This  is,  of  course,  what  one  would  expect  in  view  of  the  well- 
known  enzyme-richness  of  the  polymorphonuclear  leucocytes 
and  the  scarcity  of  enzymes  in  lymphocytes.  Erben  states  that 
the  neutrophile  cells  seem  to  be  the  chief  source  of  proteoses, 
since  their  granules  soon  disappear  in  blood  that  is  undergoing 
autolysis,  whereas  the  eosinophiles  preserve  their  granules  well, 
and  true  proteoses  are  not  present  in  blood  rich  in  mast  cells 
(i.  e.9  myeloma).  Schumm 4  found  in  the  blood  in  a  case  of 
myelogenous  leukemia  several  varieties  of  proteoses,  most 
abundant  being  the  so-called  detitero-albumose  ;  in  another  he 
also  found  peptone,  leucin,  and  ty rosin.  In  addition  he  demon- 
strated the  autolytic  nature  of  the  changes  that  occur  in  leukemic 
blood  after  death  (see  also  "  Autolysis  in  Leukemia,"  Chap.  iii). 
Most  observers  have  failed  to  find  albumose  in  the  urine  in 

1  Loc.  cit. 

2  Cent.  f.  inn.  Med.,  1904  (25),  809. 

3  For  literature  see  Erben,  Zeit.  f.  Heilk.  (Int.  Med.  Abt.),  1903  (24),  70. 

4  Hofmeister's  Beitr.,  1903  (4),  442  ;  Deut.  med.  Woch.,  1905  (31),  183. 


LEUKEMIA  257 

leukemia  ;  Askanazy l  reports  finding  what  he  describes  as  Bence- 
Jones  albumose  in  one  case  of  lymphatic  leukemia,  but  this  was 
afterward  found  to  be  a  case  of  multiple  myeloma.2  Kolisch 
and  Burian3  not  only  found  nucleoproteid  constantly,  and 
albumose  frequently,  but  in  one  case  of  lymphatic  leukemia 
they  found  histon  in  the  urine,  which  undoubtedly  came  from 
nucleoproteid  decomposition. 

Proteid  Metabolism. — Stejskal  and  Erben 4  studied  the 
metabolism  of  a  case  of  myelogenous  and  of  a  case  of  lymph- 
atic leukemia,  and  found  the  nitrogen  loss  much  greater  in  the 
myelogenous  form,  although  food-absorption  was  better  than  in 
the  lymphatic  ;  they  consider  that  proteid-destroying  forces  are 
at  work  in  myelogenous  leukemia,  similar  to  those  of  cancer 
cachexia,  so  that  nitrogenous  equilibrium  cannot  be  attained. 

As  the  most  characteristic  products  of  decomposition  of 
nucleoproteids  are  the  purin  bases,  one  would  also  expect  to 
find  them  present  in  leukemia,  and  early  writers  mention  the 
finding  of  purin  bases  and  uric  acid  in  the  blood  and  spleen. 
The  urinary  findings  in  this  respect  have  been  very  variable. 
Ebstein5  observed  the  complication  of  leukemia  with  gout, 
which  he  considered  a  coincidence,  and  also  noted  uric-acid 
concretions  in  the  urinary  passages  in  four  cases.  Numerous 
other  authors  have  described  increased  uric-acid  elimination, 
while  some  have  observed  increase  in  the  purin  bases,  either  with 
or  without  uric-acid  increase.  Magnus-Levy 6  observed  a  par- 
ticularly large  uric-acid  output  in  acute  leukemias,  but  also  found 
that  the  relation  between  the  number  of  leucocytes  and  the  uric 
acid  is  extremely  variable.  Sometimes  the  nitrogen  loss  is  very 
great — even  as  much  as  20  gm.  per  day — and,  corresponding 
with  the  destruction  of  nucleoproteids  and  the  resulting  uric-acid 
formation,  phosphoric-acid  excretion  is  often  greatly  increased — 
even  up  to  15  gm.  per  day.  On  the  other  hand,  the  results 
obtained  by  many  other  writers  have  been  in  every  respect 
extremely  variable;  some  have  found  no  increase  in  uric  acid, 
some  even  report  a  decrease ;  likewise  the  P2O5  has  been  found 
even  less  than  normal.  For  example,  in  a  carefully  studied  case 
of  lymphatic  leukemia,  Henderson  and  Edwards 7  found  during 
six  months  no  excessive  excretion  of  uric  acid  or  phosphoric 

1  Deut.  Arch.  klin.  Med.,  1900  (68),  34. 

2  See  "  Myeloma,"  Chap.  xvii. 

3  Zeit.  klin.  Med.,  1896  (29),  374  (literature  on  albuminuria  in  leukemia). 

4  Zeit.  f.  klin.  Med.,  1900(39),  151. 

3  For  literature  see  re'sume'  by  Walz  in  Cent.  f.  Pathol.,  1901  (12),  985. 

6  Virchow's  Arch.,  1898  (152),  107. 

7  Amer.  Jour,  of  Physiol.,  1903  (9),  417. 

17 


258  DISEASES  OF  THE  BLOOD 

acid.  Zalesky  and  Erben  found  likewise  no  considerable  increase 
in  the  uric  acid  in  lymphatic  leukemia,  but  in  myelogenous 
leukemia  the  uric  acid  was  much  increased ;  on  the  other  hand, 
the  amount  of  elimination  of  purin  bases  was  reversed  in  the 
two  forms,  and  creatin  was  decreased  in  both.  Lipstein l  found 
no  excessive  elimination  of  amino-acids  even  in  myelogenous 
leukemia.  An  increase  in  calcium  is  quite  constantly  observed, 
and  attributed  to  the  bone  destruction 2  occurring  in  this  disease. 
Undoubtedly  these  variations  in  results  depend  upon  the 
known  fluctuations  in  the  course  of  the  pathological  processes 
of  leukemia ;  the  number  of  leucocytes,  the  size  of  the  lymph- 
atic organs,  and  the  general  condition  of  the  patient  all  vary 
greatly  from  time  to  time,  often  with  remarkable  rapidity,  and 
the  excretion  of  products  of  metabolic  activity  must  vary  like- 
wise. It  can  hardly  be  questioned  that  the  enormous  increase 
in  the  amount  of  lymphoid  tissue  in  the  body  and  blood  must 
give  rise  to  a  greatly  increased  nuclein  catabolism,  with  con- 
sequent appearance  of  its  products  (uric  acid,  purin  bases,  and 
phosphoric  acid)  in  the  urine.  This  seems  to  be  well  demon- 
strated by  the  increased  elimination  of  uric  acid  and  purin 
bases,  together  with  a  general  increase  in  the  nitrogen  output 
that  has  been  frequently  observed  following  the  therapeutic  use 
of  x-rays  in  leukemia,  which  is  attributed  to  the  increased 
autolysis  that  x-rays  are  known  to  produce.  Lipstein  3  also 
found  an  excessive  elimination  of  amino-acids  in  the  urine  of 
leukemic  patients  treated  by  x-rays.4  According  to  Cursch- 
mann  and  Gaupp,5  the  blood  of  leukemic  patients  who  have 
been  exposed  to  arrays  contains  a  specific  leucocytotoxin, 
which  may  be  produced  by  a  process  of  autoimmunization 
against  the  leucocytic  substance  set  free  by  the  disintegrated 
leucocytes.  Capps  and  Smith6  have  obtained  similar  results. 

Char  cot's  crystals  (also  called  Charcot-Leyden  and  Charcot- 
Neumann  crystals)  represent  a  peculiar  and  striking  product  of  nuclear 
destruction  that  has  frequently  been  found  associated  with  leukemia. 

1  Loc.  cit.  inf. 

2  Stejskal  and  Erben,  loc.  cit. 

3  Hofmeister's  Beitr.,  1905  (7),  527. 

*  Literature  on  eflects  of  z-rays  in  leukemia,  see  Arneth,  Berl.  klin.  Woch., 
1905  (42),  1204;  Musser  and  Edsall,  Univ.  of  Penn.  Med.  Bull.,  1905  (18), 
174;  Kosenberger,  Munch,  med.  Woch.,  1906  (53),  209;  Williams,  Biochem. 
Jour.,  1906  (1),  249;  Lossen  and  Morawitz,  Deut.  Arch.  klin.  Med,  1905  (83), 
288;  Koniger,  Deut.  Arch.  klin.  Med.,  1906  (87),  31. 

5  Munch,  med.  Woch.,  1905  (52),  2409. 

6  Trans.  Chicago  Path.  Soc.,  1905  (6),  371 ;  see  also  Klieneberger  u.  Zoep- 
pritz,  Munch,  med.  Woch.,  1906  (53),  No.  18  ;  Milchner  u.  Wolff,  Berl.  klin. 
Woch.,  1906  (43),  No.  23. 


LEUKEMIA  259 

These  crystals  were  first  observed  by  Robin1  (1853)  in  leukemic  tissues, 
but  have  been  named  after  Charcot,  who,  with  Robin,  described  their 
properties.  They  were  described  by  Charcot  as  colorless,  refractile, 
elongated  octahedra  ;  insoluble  in  alcohol,  ether,  and  glycerin  ;  soluble 
in  hot  water,  acids,  and  alkalies  ;  size  variable,  from  0.016  by  0.005mm. 
up.  These  crystals  have  been  found  not  only  in  the  tissues  and  blood 
of  cadavers,  but  also  occasionally  in  the  freshly  drawn  blood  of 
leukemics.  Poehl2  believes  them  to  be  the  same  as  Bottcher's  spermin 
crystals,  and  derived  from  decomposed  nucleins.  Schreiner  considers 
that  these  spermin  crystals  are  phosphoric  acid  salts  of  spermin 
(CJLN),  or,  as  Majert  and  Schmidt  give  it,  C,H10N2,  with  the  structure 

CH-CH 
HN<^  /NH,   thus  being  similar  to,   although  not  identical 

XCH2— CH/ 

with,  piperazin.  The  entire  question  of  the  composition  of  spermin  is 
still  unsettled,3  however  ;  and  it  is  probable,  furthermore,  that  the  crystals 
found  in  leukemia  are  not  identical  with  the  crystals  observed  in  semen. 
Crystals  that  appear  similar  are  also  found  in  asthmatic  sputum, 
empyema,  and  ascites  fluid,  bone-marrow,  and  tumors,  and  it  has  been 
suggested  that  they  are  derived  from  or  related  to  the  oxyphile  granules 
of  theeosinophiles.*  This  view  implies  an  agreement  with  Gumprecht's 
opinion  that  the  crystals  seen  in  bone-marrow,  asthmatic  sputum,  etc.,  are 
not  spermin,  but  of  proteid  nature.  As  can  be  seen,  the  nature  and  signifi- 
cance of  Charcot' s  crystals  are,  at  the  present  time,  quite  undetermined. 

Summary. — The  chemical  changes  observed  in  leukemia 
depend  upon  the  excessive  quantity  of  leucocytes  and  lymphoid 
tissue,  which  undergo  processes  of  disintegration  at  irregular 
intervals,  with  the  result  that  the  products  of  nucleoproteid 
destruction  (uric  acid,  purin  bases,  and  phosphoric  acid)  appear 
in  the  urine  in  increased  quantities.  As  the  large  neutrophiles 
contain  abundant  autolytic  enzymes,  the  products  of  cell  autol- 
ysis  (proteoses,  amino-acids,  and  products  of  nucleoproteid 
destruction)  may  appear  at  times  in  the  urine  and  in  the  blood ; 
because  of  the  small  amount  of  such  enzymes  in  the  lympho- 
cytes, these  changes  are  all  much  less  marked  in  lymphatic 
leukemia.  Charcot' s  crystals,  which  are  perhaps  derived  from 
leucocytic  nucleoproteids,  may  be  found  in  the  blood  and  tissues, 
The  changes  in  the  red  cells  are  chiefly  those  of  a  secondary 
anemia,  with  occasionally  some  chlorotic  features.  The  chem- 
ical findings  of  leukemia  throw  no  light  whatever  upon  the  cause 
of  the  disease. 

Hodgkin's  disease  (pseudo-leukemia)  shows  only  the  evidences 

1  Earlier  literature  given  by  Ewing,  "  Clinical  Path,  of  Blood,"  1901,  p. 
218 ;  and  by  v.  Limbeck,  "  Clinical  Path,  des  Blutes,"  1896,  p.  318. 

2  Deut.  med.  Woch.,  1895  (21),  475. 

3  Literature,  see  Hammarsten,  Amer.  Transl.,  1904,  p.  420. 

4  Literature,  see  Floderer,  Wien.  klin.  Woch.,  1903  (16),  276 ;  Predtets- 
chensky,  Zeit.  klin.  Med.,  1906  (59),  29. 


260  DISTURBANCES  OF  CIRCULATION 

of  a  secondary  anemia,  without  the  chemical  changes  of  either 
leukemia  or  pernicious  anemia.  There  seems  to  have  been  little 
study  of  the  chemical  processes  of  this  disease.  Moraczewski l 
reports  a  study  of  metabolism  in  one  case,  which  showed  some 
retention  of  nitrogen  and  calcium,  with  little  change  in  the  phos- 
phorus and  purin  bases  in  the  urine. 

HYPEREMIA 
ACTIVE   HYPEREMIA 

This  condition  is  associated  with  but  few  chemical  changes. 
Certain  chemicals  may  cause  active  hyperemia  ;  some  locally,  as 
in  the  case  of  irritants,  such  as  alcohol,  ether,  ammonia,  mus- 
tard, etc.,  which  act  either  by  producing  a  local  vasodilator 
stimulus  or  by  paralyzing  the  vasoconstrictors.  Other  sub- 
stances may  produce  active  hyperemia  in  special  vascular  areas, 
e.  g.,  cantharides  causes  active  hyperemia  in  the  kidneys,  prob- 
ably because  of  its  elimination  through  these  organs  ;  pilocarpin 
causes  active  hyperemia  in  the  salivary  glands  and  skin,  which 
is  associated  with  increased  function.  In  general,  functional 
activity  is  associated  with  active  hyperemia,  and  Gaskell 2  has 
suggested  that  this  is  due  to  atonicity  of  the  vascular  muscle, 
the  result  of  decreased  alkalinity  of  the  lymph  flowing  away 
from  the  active  organ  along  the  vessel-walls,  it  having  been 
found  that  alkalies  cause  a  tonic  contraction  and  acids  an 
atonic  dilatation  of  arterial  muscle. 

Pathological  active  hyperemia  is  seldom  of  long  enough  dura- 
tion to  lead  to  any  alterations  in  the  tissues  in  which  it  occurs. 
The  blood  itself  remains  unchanged,  except  that  the  venous 
blood  going  from  the  part  contains  much  less  CO2  and  more 
oxygen  than  usual,  because  more  oxygen  is  brought  to  the 
tissues  than  can  be  used. 

PASSIVE   HYPEREMIA 

Passive  hyperemia  is  almost  equally  unassociated  with  chem- 
ical changes,  especially  in  its  etiology,  which  depends  almost 
solely  upon  mechanical  factors.  Some  chemical  alterations 
result,  however,  from  the  changes  in  the  stagnating  blood,  which 
may,  if  the  obstruction  to  outflow  is  severe,  become  of  venous 
character  in  the  capillaries  of  the  congested  area.  Oxidation 
in  the  tissues  is,  therefore,  impaired,  and  some  fatty  changes  may 
result,  e.  g.,  in  the  center  of  congested  liver  lobules.  Waste 

1  Virchow's  Arch.,  1898  (151),  22. 

2  Quoted  by  Lazarus-Barlow,  "  Manual  of  General  Pathology,"  1904,  p.  126. 


HYPEREMTA  261 

products  accumulate,  and  possibly  noxious  products  of  metab- 
olism are  formed  under  lack  of  oxidation ;  either  from  these 
causes  or  solely  from  pressure  and  lack  of  nutrition  there  is  a 
tendency  to  atrophy  of  the  more  specialized  parenchymatous 
cells,  and  a  proliferation  of  connective  tissues.  The  atrophy  of 
parenchyma  is  seen  particularly  in  the  liver,  the  increase  of 
connective  tissue  in  the  spleen.1  In  the  kidney  neither  atrophy 
nor  stroma  proliferations  are  pronounced,  but  the  renal  function 
is  greatly  impaired,  since  it  depends  upon  the  amount  and  quality 
of  the  blood  brought  to  the  kidney.  Whether  connective-tissue 
proliferation  in  hyperemia  depends  upon  overnutrition  or  upon 
irritation  by  waste-products,  or  is  compensatory  to  parenchyma- 
tous atrophy,  may  be  looked  upon  as  still  an  open  question. 
Probably  only  the  first  two  factors  apply  to  the  connective-tissue 
growth  observed  in  the  congested  spleen,  the  clubbing  of  the 
fingers  in  congenital  heart  disease,  or  the  thickening  of  the  sub- 
cutaneous tissues  in  passive  congestion  of  the  lower  extremities. 
The  edema  of  passive  congestion  seems  to  result  partly  from 
mechanical  forces  and  partly  from  the  high  osmotic  pressure  that 
develops  in  the  underoxygenated  tissues  (see  "Edema,"  Chap.  xii). 
Changes  in  the  Blood. — Venous  blood  differs  from 
arterial,  not  only  in  its  increased  load  of  CO2  and  other  waste- 
products,  but  also  in  other  ways.  Venous  blood  generally  clots 
less  readily  than  arterial  blood.2  It  contains  more  diffusible 
alkali  because  the  CO2  combines  with  and  tears  away  part  of 
the  bases  that  are  held  by  the  proteids,  especially  in  the  cor- 
puscles, and  so  alkaline  carbonates  are  formed  and  enter  the 
plasma.  Blood  from  the  jugular  vein  on  this  account  contains 
20-25  per  cent,  more  diffusible  alkali  than  carotid  blood  (Ham- 
burger 3 ).  Since  the  bactericidal  power  of  the  blood  has  been 
shown  to  increase  directly  with  the  alkalinity,  this  property 
may  be  of  importance  in  pathology.  For  example,  the  relative 
infrequency  of  infections  in  the  right  side  of  the  heart  may  not 
depend  solely  upon  lessened  liability  to  endocardial  damage,  as 
generally  considered,  but  is  possibly  due  in  part  to  the  greater 
bactericidal  power  of  venous  blood.  The  same  property  prob- 
ably explains  the  favorable  results  obtained  in  the  treatment  of 
local  infections  by  artificially  produced  passive  congestion.4 

1  See  Christian,  Jour.  Amer.  Med.  Assoc.,  1905  (45),  1615. 

2  Vierordt  (Arch.  f.  Heilk.,  1878  (19),  193)  found  coagulation  faster  in  the 
blood  in  passive  congestion  than  in  normal  venous  blood ;  but  Hasebrock  (Zeit. 
f.  Biol.,  1882  (18),  41)  found  that  if  the  stasis  is  protracted,  the  coagulation 
becomes  delayed  because  of  the  excess  of  CO2. 

3  Virchow's  Arch.,  1899  (156),  329;  also,  "Osmotischer  Druck  und  lonen- 
lehre,"  1902,  p.  280. 

4  See  Bier,  "  Hyperaemie  als  Heilmittel,"  Leipsic,  1903. 


262  DISTURBANCES  OF  CIRCULATION 

v.  Fodor 1  found  that  animals  surviving  infections  showed  an 
increased  blood  alkalinity,  whereas  in  those  that  died,  the  alka- 
linity was  decreased  ;  also,  he  found  the  resistance  increased  by 
intravenous  injections  of  alkalies.  Other  observers 2  have  noted 
a  decrease  in  resistance  after  injecting  acids  into  the  blood. 
According  to  Calabrese,  the  alkalinity  of  the  blood  increases  in 
immunization  of  animals  against  toxins,  while  Cantani  found 
the  injection  of  toxin  followed  by  a  decrease  in  alkalinity. 
Hamburger  has  shown  that  the  bactericidal  power  of  the  blood 
may  be  increased  in  vitro  by  shaking  it  with  CO2,  as  a  result 
of  the  increased  alkalinity,  aided,  perhaps,  by  some  slight 
bactericidal  power  of  the  CO2  itself;  he  also  found  the  blood 
more  strongly  bactericidal  in  venous  congestion  than  normally, 
and  the  lymph  from  a  congested  part  was  also  found  more 
strongly  bactericidal  than  normal  lymph.  Hamburger3  has 
also  found,  however,  that  chemotaxis  is,  if  anything,  slightly 
decreased  under  the  influence  of  CO2,  as  also  is  phagocytosis ; 
large  amounts  of  CO2  may  reduce  the  phagocytic  power  for  coal 
particles  by  25—50  per  cent.  Hamburger's  results  as  to  the 
bactericidal  power  of  human  blood  in  venous  stasis  have  been 
more  recently  confirmed  by  Laqueur.4 

The  blood  in  the  veins  and  capillaries  in  passive  congestion 
is  generally  richer  in  corpuscles  than  normal,  perhaps  because 
of  some  loss  of  water,5  although  this  is  not  constant,  apply- 
ing particularly  to  more  recent  or  more  local  processes  ;  in 
long-continued  stasis,  as  in  congenital  heart  disease,  the  blood 
may  be  diluted.6  In  the  concentrated  blood  of  passive  con- 
gestion the  corpuscles  may  number  six  to  eight  millions  per 
cubic  millimeter,  while  the  concentration  of  the  solids  of  the 
serum  may  be  at  the  same  time  reduced  (Krehl).  The  viscosity 
of  such  blood  is  higher  than  that  of  normal  blood.7 

THROMBOSIS 

The  chemistry  of  thrombosis  in  most  respects  resolves  itself 
into  the  chemistry  of  fibrin  formation,  a  subject  which  is  so  ex- 
tensively considered  in  most  treatises  on  physiological  chemistry 
and  physiology  that  it  does  not  seem  desirable  to  give  here 

1Cent  f.  Bakt.,1890(7),  753. 

2  Literature,  see  Hamburger  (toe.  cit),  p.  281. 

3  Virchow's  Arch.,  1899  (156),  329. 
4Zeit.  exp.  Path.  u.  Therap.,  1905  (1),  670. 
5Grawitz,  Deut.  Arch.  f.  klin.  Med.,  1895  (54),  588. 

6  See  Krehl,  "  Pathologische  Physiologic,"  1904,  p.  201. 

7  Determann,  Zeit.  klin.  Med.,  1906  (59),  H.  2-4. 


FIBRIN  FORMATION  263 

anything  more  than  the  essential  principles  involved  in  the  clot- 
ting of  the  blood,  as  now  understood,  as  an  introduction  to  the 
consideration  of  the  same  process  as  it  occurs  under  pathologi- 
cal conditions.  In  spite  of  innumerable  investigations,  our 
knowledge  of  the  actual  participants  and  processes  involved  in 
the  formation  of  fibrin  is  in  a  very  unsatisfactory  and  fragment- 
ary state.  Some  facts  seem  well  established,  however,  and  we 
have  a  general  idea  of  the  subject  that  may  be  applied  with 
advantage  to  the  consideration  of  thrombosis. 

FIBRIN    FORMATION1 

Several  different  substances  seem  to  be  concerned  in  the  formation  of 
fibrin,  of  which  the  first  of  importance  is  its  antecedent,  fibrinogen. 
Fibrinogen  is  a  simple  proteid,  related  to  the  globulins,  and  differing 
chiefly  in  its  ready  coagulability,  not  only  by  fibrin  ferment,  but  also  by 
heat,  salts,  and  other  coagulating  agencies.  By  itself,  however,  it  shows 
no  tendency  to  coagulate  spontaneously.  According  to  Mathews,2 
fibrinogen  is  formed  chiefly  in  the  intestinal  walls  from  the  leucocytes. 
Acted  upon  by  the  fibrin-ferment,  it  yields  the  characteristic  insoluble 
proteid,  fibrin  ;  probably  the  change  consists  in  a  cleavage  of  the  fibrino- 
gen molecule  into  fibrin  and  a  small  amount  of  a  soluble  proteid.  Fibrin 
resembles  in  its  insolubility  the  proteids  coagulated  by  heat,  alcohol,  etc., 
but  when  kept  aseptically  for  some  time,  it  becomes  again  dissolved  ;  this 
process  of  fibrinolysis  probably  depends  upon  proteolytic  enzymes  which 
fibrin,  in  common  with  other  substances  of  similar  physical  nature,  has 
the  property  of  dragging  out  of  solution  and  holding  firmly.  Undoubt- 
edly entangled  leucocytes  are  also  an  important  factor  in  the  fibrin- 
olysis.3 

Theories  of  Fibrin  Formation. — The  great  problem  is  the  nature 
and  the  place  and  manner  of  origin  of  the  fibrin-forming  enzyme, 
generally  called  fibrin-ferment  (also  p losmose  and  coaguliri).  It  has  been 
conclusively  shown  that  the  agent  causing  the  formation  of  fibrin  from 
fibrinogen  is  a  true  enzyme,  but,  as  with  the  other  enzymes,  it  is  not 
known  whether  fibrin-ferment  is  a  nucleoproteid  (Pekelharing)  or  any 
other  sort  of  a  proteid.  The  best  known  and  most  fundamental  theory 
of  the  origin  and  nature  of  fibrin-ferment  is  that  of  Alexander  Schmidt, 
which  may  be  briefly  described  as  follows:  The  ferment,  Schmidt 
believes,  exists  in  the  plasma  in  an  inactive  (prozyme  or  zymogeri)  form, 
which  he  calls  prothrombin.  Upon  disintegration  of  the  leucocytes  there 
is  set  free  a  substance,  which,  acting  upon  the  prothrombin,  converts  it 
into  the  active  thrombin  ;  this  activating  agent  Schmidt  designates  as 
the  zymoplastic  substance.  With  various  modifications  this  theory  stands 

1  For  literature  and  full  discussion  see  Hammarsten's  Physiological  Chemis- 
try;  more  recent  literature  by  Morawitz,  Ergebnisse  der  Physiol.,  Abt.  1,  1904 
(4),  307;  and  Blum,  Cent,  f"  Path.,  1904  (15),  385.  Re'sum^  of  recent  work 
by  Leo  Loeb,  Medical  News,  1905  (86),  577. 

2Amer.  Jour.  Physiol.,  1899  (3),  53;  a  different  view  is  held  by  Doyon, 
Morel  and  Kareff  (Jour.de  physiol.,  1906  (8),  783) 

3  See  Morawitz,  loc.  cit. ;  also  Rulot,  Arch,  internat.  d.  Physiol.,  1904  (1), 
152. 


264  DISTURBANCES  OF  CIRCULATION 

to  the  present  day  as  best  explaining  the  facts  concerning  fibrin  forma- 
tion with  which  we  are  familiar. 

It  having  been  shown  that  calcium  facilitates  the  formation  of  fibrin, 
Pekelharing  advanced  the  idea  that  the  prothrombin  does  not  exist  in  the 
plasma,  but  is  liberated  from  the  leucocytes,  and,  combining  with  the 
calcium  of  the  plasma,  forms  the  thrombin.  Morawitz  considers  three 
substances  necessary  for  the  formation  of  thrombin  :  (1)  the  prothrombin 
or  thrombogen,  which  he  believes  originates  in  the  blood-plates  ;  (2)  the 
zymoplastic  substance  or  thrombokinase,  which  is  liberated  from  the  leuco- 
cytes into  the  plasma  ;  (3)  calcium  salts.  The  chief  differences,  there- 
fore, are  not  concerning  the  nature  of  the  thrombin,  but  the  manner  of 
its  origin,  and  whether  the  prothrombin  arises  from  the  leucocytes,  the 
plasma,  or  the  platelets.  It  seems  quite  probable,  however,  that  pro- 
thrombin may  occur  in  all  these  constituents  of  the  blood ;  since 
coagulation  occurs  in  the  lymph,  which  contains  no  platelets,  the  pro- 
thrombin evidently  is  not  derived  solely  from  these  elements.  It  will 
not  serve  our  purpose,  however,  to  go  further  into  the  hypotheses  and 
disputes  over  these  questions,  which  are  detailed  more  fully  in  the 
literature  previously  cited. 

The  question  has  been  raised  as  to  whether  the  leucocytes  secrete 
their  fibrin-forming  constituent  (be  it  thrombokinase  or  prothrombin  is 
a  matter  of  minor  importance  to  the  pathologist)  or  liberate  it  only  after 
their  disintegration.  So  far  as  pathological  processes  go,  the  latter  seems 
to  be  the  case,  the  disintegration  apparently  occurring  whenever  the 
leucocytes  come  in  contact  with  a  foreign  body  or  with  dead  and  injured 
tissues. J 

Tissue  Coagulins, — Among  the  other  points  that  are  of  importance 
in  pathological  conditions  is  the  fact  that  not  only  leucocytes,  but  also 
tissue-cells,  can  liberate  fibrin-forming  substances  (coagulins  is  the  non- 
committal term  applied  by  Loeb).  These  tissue-coagulins  are  present  in 
tissue  extracts  and  are  liberated  whenever  the  tissues  are  injured  ;  muscle 
is  rich  in  coagulin,  as  are  also  the  liver  and  kidney,  and,  which  is  partic- 
ularly important,  the  blood-vessel  wall  (L.  Loeb).  Pieces  of  these 
tissues  placed  in  contact  with  fibrinogen  solution  will  bring  about  prompt 
clotting.  Another  important  fact  is  that  the  coagulins,  whether  derived 
from  leucocytes  or  from  the  tissues,  have  a  certain  degree  of  specificity 
— that  is,  they  act  solely  or  most  rapidly  with  fibrinogen  of  blood  of  the 
species  from  which  they  are  obtained.2  In  some  instances  this  specific- 
ity is  absolute,  but  more  generally  (particularly  in  the  mammalia)  it  is 
only  relative.  Loeb  also  found  that  the  amount  of  tissue  coagulin  was 
not  decreased  in  organs  altered  by  phosphorus-poisoning,  although  during 
experimental  autolysis  the  coagulins  disappear.  When  tissue  coagulins 
and  blood  coagulins  act  together,  the  effect  is  greater  than  the  sum  of 
their  independent  actions,  indicating  the  probability  that  they  combine 
in  some  way  to  produce  a  particularly  active  coagulin.  The  blood 
coagulins  are  quite  different  from  the  tissue  coagulins  in  many  important 
respects,  and  the  coagulins  cannot  be  looked  upon  as  a  single  substance 
of  different  origins. 

Blood-platelets.3 — It  is  still  undetermined  just  what  part  the  platelets 

1  See  L.  Loeb,  loc.  cit. 

2  Leo  Loeb,  Univ.  of  Penn.  Med.  Bull.,  1904  (16),  382;  Muraschew,  Deut. 
Arch.  klin.  Med.,  1904  (80),  187. 

3  Earlier  literature,  see  Schwalbe,  Ergebnisse  der  Pathol.,  1902  (8),  150 : 
and  Lowit,  ibid.,  1895  (2),  642. 


COAGULATION  OF  THE  BLOOD  265 

play  in  coagulation.  The  well-known  observation  that  in  thrombosis  the 
fibrin  is  often  first  formed  about  masses  of  platelets  clinging  to  the  wall 
of  the  vessel  indicates  that  they  participate  in  the  process,  and  Bizzozero 
and  others  have  maintained  that  the  platelets  and  not  the  leucocytes  are 
the  source  of  the  prothrombin.  Numerous  studies  on  the  relation  of  the 
platelets  to  disease  conditions  have  indicated  a  certain  parallelism  bs- 
tween  their  number  and  the  tendency  to  coagulation  observed  in  the 
various  diseases  (Welch).  Pratt,1  however,  found  that  the  number  of 
platelets,  bore  no  relation  to  the  coagulability  of  the  blood  ;  and  lymph, 
which  is  free  from  platelets,  will  coagulate.  It  is,  therefore,  probable 
that  platelets  are  one,  but  not  the  sole,  source  of  thrombin.  Kemp 2  con- 
cludes, from  a  thorough  review  of  the  subject,  that  the  blood-platelets  are 
usually  normal  or  subnormal  in  number  during  acute  infectious'diseases, 
but  increase  rapidly  if  the  disease  terminates  by  crisis ;  in  pernicious 
anemia  the  number  is  always  greatly  diminished,  although  in  secondary 
anemias  they  may  sometimes  be  increased  ;  in  purpura  hcemorrhagica  the 
number  of  plates  is  enormously  diminished,  which  is  perhaps  related  to 
the  slowness  of  the  clotting  of  the  blood  in  this  condition. 

Calcium  Salts. —  The  exact  significance  of  calcium  in  fibrin  formation 
is  also  unsettled.8  Blood  from  which  the  calcium  has  been  precipitated 
will  not  coagulate,  and  the  addition  of  calcium  salts  will  promptly  cause 
it  to  do  so  ;  furthermore,  the  coagulability  of  the  blood,  whether  normal 
or  below  normal,  may  be  greatly  increased  by  the  administration  of 
calcium  salts  to  the  subject  by  mouth  (Wright  * ).  The  various  hypotheses 
advanced  to  explain  the  way  in  which  calcium  influences  the  clotting 
process  are  not  in  agreement.  Perhaps  the  most  probable  hypothesis  is 
that  the  calcium  ions  are  necessary  for  the  transformation  of  prothrom- 
bin into  thrombin  (Pekelharing,  Hammarsten,  Morawitz),  the  thrombin 
consisting  of  a  compound  of  prothrombin,  calcium  salts,  and  thrombo- 
kinase. 

Modification  of  Coagulability. — Another  important 
matter  for  consideration  is  the  effect  of  various  substances  in 
modifying  the  rate  or  completeness  of  the  coagulation  of  the 
blood.  In  the  first  place,  we  have  the  well-known  fact  that  if 
blood  is  drawn  into  a  glass  vessel  well  coated  with  oil  or  vaseline, 
through  a  cannula  similarly  protected,  no  coagulation  will  take 
place ;  but  if  any  unoiled  foreign  substance  enters,  even  particles 
of  dust,  coagulation  begins  at  once.  The  explanation  is  that 
the  leucocytes  do  not  liberate  their  coagulating  substances  until 
they  have  been  injured  by  contact  with  some  foreign  body,  and 
the  experiment  proves  the  importance  of  this  action  of  the 
leucocytes,  as  well  as  explaining  why  the  blood  does  not  coagu- 
late during  life.  The  classical  experiment  of  the  ligation  of  a 
vein  without  injury  to  the  endothelium,  which  permits  the  blood 

1  Jour,  of  Med.  Research,  1903  (10),  120. 

2  Jour.  Amer.  Med.  Assoc.,  1906  (46),  1022. 

3  See  Hammarsten,  Zeit.  physiol.  Chem.,  1896  (22),  333. 

4  British  Med.  Jour.,  1894   (ii),  57;  also  Boggs,  Deut.  Arch.  klin.  Med., 
1904  (79),  539. 


266  DISTURBANCES  OF  CIRCULATION 

to  remain  stagnant  for  a  long  period  without  clotting,  depends 
upon  the  same  fact,  namely,  that  normal  endothelium  neither 
liberates  coagulin  itself  nor  injures  the  leucocytes  so  that  they 
disintegrate.  Loeb  recalls  the  observation  of  Overton  that 
lipoids  are  important  constituents  of  the  cell  membranes,  and 
suggests  a  similarity  between  the  vessel  lining  and  the  oiled 
cannula.  The  suggestion  that  the  vessel  walls  contain  an  anti- 
coagulin  could  not  be  confirmed  by  Loeb.  Since  leucocytes  are 
constantly  undergoing  disintegration  in  the  blood  and  tissues 
under  normal  conditions,  it  might  be  asked  why  they  do  not 
cause  clotting  then  and  there.  In  explanation  Loeb  advances 
his  observation  that  the  coagulins  are  destroyed  during  cell 
autolysis,  and  suggests  that  when  leucocytes  normally  disintegrate, 
the  coagulins  are  first  destroyed  by  autolysis.  It  has  also  been 
shown  that  the  cells  and  serum  contain  substances  which  inhibit 
or  prevent  coagulation,  and  it  is  possible  that  these  play  an 
important  part  under  normal  conditions  in  preventing  coagu- 
lation by  products  of  cell  disintegration,  much  as  other  anti- 
enzymes  are  supposed  to  act  in  preventing  autodigestion  of 
living  cells. 

Coagulation  of  drawn  blood  may  be  retarded  experimentally 
by  removal  of  the  calcium  by  precipitation  as  oxalate,  fluoride, 
etc. ;  also  by  diminishing  the  oxygen  and  increasing  the  CO2, 
by  addition  of  solutions  of  neutral  salts  in  large  amounts,  by 
diluting  greatly  with  water,  or  by  keeping  the  blood  cold. 
Coagulation  may  be  hastened  by  moderate  heat,  by  whipping, 
exposure  to  air,  by  contact  with  much  foreign  matter,  and  by 
the  addition  of  watery  extracts  from  many  different  tissues  and 
organs.1  Of  particular  interest  pathologically  is  the  retardation 
of  coagulation  that  follows  injections  of  proteoses  (the  so-called 
"  peptone "  solution)  and  also  by  various  other  proteid-con- 
taining  solutions,  such  as  organ  extracts,  bacterial  toxins,  snake 
venoms,  eel  serum,  extract  of  leeches  or  of  Uncinaria,  impure 
nucleoproteid  solutions,  or  solutions  of  various  colloids.  Most 
of  these  substances  (e.  g.,  peptone,  eel  serum)  cause  reduction 
of  coagulability  when  injected  into  animals,  and  are  without 
effect  on  blood  removed  from  the  body.  A  few,  however, 
prevent  coagulation  of  drawn  blood  (snake  venom,  extract  of 
leeches).  When  substances  of  the  first  class  are  injected  in 
sufficient  quantities,  there  occurs  first  a  period  of  accelerated 
coagulation  which  may,  particularly  in  the  case  of  organ  extracts, 
cause  prompt  death  from  intravascular  clotting ;  if  the  animal 
survives,  there  follows  a  period  of  decrease  or  total  inhibition 
lSee  Conradi,  Hofmeister's  Beitr,,  1901  (1),  136. 


COAGULATION  OF  THE  BLOOD  267 

of  coagulability  of  the  blood,  both  within  the  vessels  and  after 
removal  from  the  body.  The  first  period  of  increased  coagula- 
bility undoubtedly  depends  upon  the  formation  of  a  large  amount 
of  fibrin-ferment,  but  it  has  not  yet  been  satisfactorily  explained 
how  the  inhibition  of  coagulation  is  produced.  Apparently  the 
fibrin-ferment  formed  at  first  is  rapidly  destroyed,  but  it  is 
thought  by  some  that  it  is  converted  into  a  substance  that 
neutralizes  the  fibrin-ferment  that  may  be  formed  later,  or  that 
a  true  anticoagulin  is  formed.  It  is  also  among  the  possibilities 
that  all  the  available  prothrombin  or  thrombokinase  is  used  up 
during  the  first  stage  of  acceleration.  As  before  mentioned,  the 
blood  and  tissues  contain  substances  that  inhibit  coagulation,  and 
it  may  be  that  these  are  secreted  in  excessive  amounts.  It 
has  been  found  that  in  animals  deprived  of  the  liver  no  coagu- 
lation-inhibiting substances  are  formed  in  the  blood  after  injec- 
tion of  proteoses,  hence  Delezenne  believes  that  the  substances 
of  this  class  act  by  causing  a  destruction  of  leucocytes,  thus 
liberating  a  substance  which  increases  coagulation  and  also 
another  substance  retarding  coagulation ;  the  first  of  these  is 
destroyed  by  the  liver,  leaving  the  retarding  substance  to  act 
unopposed.1  Leech  extract  (hirudiri)  prevents  clotting  by  means 
of  an  antiferment  action,  combining  with  the  thrombin.  Snake 
venom,  however,  acts  upon  the  thrombokinase  (Morawitz). 

Coagulability  of  the  Blood  in  Disease. — In  disease 
the  alterations  in  the  coagulability  of  the  blood  depend  upon 
much  the  same  factors.  The  high  coagulability  in  lobar  pneu- 
monia is  undoubtedly  caused,  at  least  in  part,  by  an  excessive 
formation  of  fibrin-ferment  through  the  extensive  disintegration 
of  leucocytes.  In  all  conditions  associated  with  suppuration 
and  leucocytosis  the  amount  of  fibrinogen  is  also  increased. 
The  fluidity  of  the  blood  in  septicemia  is  probably  dependent 
upon  the  appearance  of  the  coagulation-inhibiting  phase  that 
follows  the  action  of  the  products  of  cell  destruction,  including 
among  them  proteoses.  In  this  connection  should  be  mentioned 
the  observation  of  Conradi,2  who  found  that  among  the  products 
of  autolysis  is  a  coagulation-inhibiting  substance  which  is  not 
destroyed  by  heat,  diffuses  readily,  and  in  general  behaves  unlike 
the  proteids.  This  or  similar  substances  may  well  play  a  part 
in  affecting  coagulation  in  infectious  diseases.  It  may  also  be 
mentioned  that  animals  soon  acquire  an  immunity  against 

1  The  manner  in  which  gelatin  injections  cause  an  increase  in  the  blood 
coagulability  is  not  yet  understood  (see  Boggs,  Deut.  Arch.  klin.  Med.,  1904 
(79),  539). 

2  Hofmeister's  Beitr.,  1901  (1),  137. 


268  DISTURBANCES  OF  CIRCULATION 

proteoses,  so  that  their  inhibiting  influence  is  no  longer  shown. 
This  corresponds  to  the  observation  of  Kanthack  l  that  immune 
serum  against  venom  neutralizes  very  effectively  the  anticoagu- 
lating  principle  of  venom  ;  an  amount  of  antiserum  altogether 
insufficient  to  neutralize  the  toxic  properties  of  venom  will 
neutralize  its  property  of  preventing  clotting.  The  bacterial 
products  may  also  modify  coagulation,  and  L.  Loeb  2  has  found 
that  different  organisms  are  unequally  effective  in  this  respect, 
Staphylococcus  aureus  being  much  more  powerful  in  causing 
coagulation  than  any  others  tested  ;  typhoid,  diphtheria,  tubercle, 
and  xerosis  bacilli  and  streptococci  being  without  any  apparent 
effect,  while  pyocyaneus,  prodigiosus,  and  colon  bacilli  occupy 
an  intermediate  position.  Furthermore,  after  the  organisms  are 
killed  by  boiling,  this  effect  is  greatly  reduced,  showing  that  it 
does  not  depend  merely  upon  the  mechanical  action  of  the 
bacteria,  but  probably  upon  bacterial  products  contained  in  the 
culture-media. 

After  phosphorus-poisoning  the  blood  may  become  non-coag- 
ulable,  which,  Jacoby 3  found,  was  due  to  an  absence  of  fibrino- 
gen  in  the  blood;  this  Jacoby  attributed  to  a  fibrinogen-destroying 
ferment  in  the  liver.  As  yet  this  is  the  only  known  example  of 
non-coagulability  due  to  absence  of  fibrinogen,  with  the  excep- 
tion of  Doyon's4  similar  finding  in  chloroform  necrosis  of  the 
liver.  In  other  instances  of  decreased  coagulability  the  fibrino- 
gen is  present,  generally  in  normal  amounts.  After  death  the 
blood  becomes  incoagulable  because  the  fibrinogen  is  destroyed 
through  a  process  similar  to  that  of  fibrinolysis ; 5  this  fibrinol- 
ysis  may  be  complete  as  early  as  ten  hours  after  death.  The 
other  proteids  of  the  blood  do  not  seem  to  be  correspondingly 
attacked.  Thrombokinase  is  also  scanty  in  cadaver  blood,  but 
there  seem  to  be  no  coagulation-inhibiting  substances  present. 

Pfeiffer 6  estimated  the  fibrin  content  of  the  blood  in  disease, 
and  found  it  increased  in  diseases  with  leucocytosis  (pneumonia, 
rheumatism,  erysipelas,  scarlet  fever),  except  leukemia,  where  it 
was  normal ;  in  diseases  without  leucocytosis  (typhoid,  malaria, 
nephritis),  the  fibrin  was  normal  in  amount.  Stassano  and 
Billon 7  have,  furthermore,  shown  that  the  amount  of  fibrin-fer- 

1  Cited  by  Lazarus-Barlow,  p.  141. 

2  Jour.  Med.  Research,  1903  (10),  407. 

3  Zeit.  physiol.  Chem.,  1900  (30),  175;  also  Doyon  et  aL,  Compt.  Eend.  Soc. 
Biol.,  1905  (58),  493. 

.*  Compt.  Rend.  Soc.  Biol.,  1905  (58),  704. 

5  Morawitz,  Hofmeister's  Beitr.,  1906  (8),  1. 

6  Zeit.  klin.  Med.,  1897  (33),  214 ;  Cent.  f.  inn.  Med.,  1898  (19),  1. 

7  Compt.  Rend.  Soc.  Biol.,  1903  (55),  511. 


THROMBOSIS  269 

ment  varies  directly  with  the  number  of  leucocytes  in  the  blood. 
Kollmann  l  found  an  increase  in  the  fibrin  in  eclampsia,  which 
Lewinski 2  could  not  substantiate.  In  experimental  infections 
of  animals  Langstein  and  Mayer 3  found  a  specific  increase  in 
pneumococcus  sepsis,  which  undoubtedly  bears  an  important 
relation  both  to  the  characteristic  fibrinous  nature  of  the  alveo- 
lar exudate  in  pneumonia,  and  the  striking  amount  of  fibrin  found 
in  pneumococcus  pleuritis,  peritonitis,  etc.  Mathews 4  found  an 
increase  in  the  fibrin  with  all  experimental  suppurations. 

The  coagulation  time  of  the  blood  may  be  determined 
experimentally  by  methods  devised  by  Vierordt,5  A.  E.  Wright  ,6 
and  by  Brodie  and  Russell,7  the  last  named  being  considered  the 
best  by  Murphy  and  Gould.8  The  average  time  of  coagulation 
is  between  three  and  six  minutes.  In  jaundice  a  delayed 
coagulation  time  has  generally  been  observed,  but  was  not  con- 
stantly found  by  Murphy  and  Gould. 

THE   FORMATION    OF  THROMBI 

If  we  apply  the  facts  brought  out  in  the  preceding  discussion 
relative  to  the  factors  in  the  coagulation  of  blood,  to  the  man- 
ner and  conditions  under  which  thrombi  are  formed  in  the 
circulating  blood,  we  find  explanations  for  many  of  the 
features  of  thrombosis.  Welch9  describes  the  steps  in  the 
formation  of  a  thrombus  after  injury  to  the  vessel-wall,  as  fol- 
lows :  First,  there  is  an  accumulation  of  blood-platelets  adher- 
ing to  the  wall  at  the  point  of  injury.  Leucocytes,  which  may 
be  present  in  small  numbers  at  the  beginning,  rapidly  increase 
in  number,  collecting  at  the  margins  of  the  platelet  masses  and 
between  them.  Not  until  the  leucocytes  have  accumulated 
does  the  fibrin  appear.  As  Welch  remarks,  these  findings 
afford  no  conclusive  evidence  as  to  whether  fibrin-ferment  is 
formed  from  the  leucocytes  or  from  the  platelets,  but  since  the 
fibrin  does  not  appear  until  after  the  leucocytes  have  accumulated, 
and  also  since  small  thrombi  may  consist  solely  of  platelets  with- 
out fibrin,  it  seems  probable  that  the  leucocytes  must  be  looked 
upon  as  the  chief  source  of  the  ferment.  Sometimes  small  clots 
may  form  without  the  apparent  participation  of  either  platelets 
or  leucocytes.  These  purely  fibrinous  thrombi  seem  to  start  from 

1  Cent.  f.  Gynak.,  1897  (21),  341.  2  Pfliiger's  Arch.,  1903  (100),  611. 

3  Hofmeister's  Beitr.,  1903  (5),  69.        4  Amer.  Jour.  Physiol.,  1899  (3),  53. 
5  Arch.  f.  Heilk.,  1878  (19),  193.  6  Brit.  Med.  Jour.,  1894  (i),  237. 

7  Jour,  of  Physiol.,  1897  (21),  403. 

8  Boston  Med.  and  Surg.  Jour.,  1904  (151),  45. 

9  Albutt  System,   vol.   6,  complete  discussion  of  the  general  features   of 
thrombosis;  also  see  Jores,  Ergebnisse  der  Pathol.,  1988  (5),  1. 


270  DISTURBANCES  OF  CIRCULATION 

injured  endothelial  cells,  particularly  in  inflammatory  conditions, 
such  as  pneumonic  lungs,  and  give  the  impression  that  the 
coagulin  is  derived  from  the  endothelial  cells. 

The  process  of  clotting  in  the  stoppage  of  hemorrhage  offers 
some  differences  from  intravascular  clotting,  in  that  the 
coagulins  of  the  tissue-cells  also  come  into  play.  It  is  rather 
difficult  to  determine  how  much  of  the  coagulation  depends  on 
these,  and  how  much  on  the  coagulins  of  the  leucocytes,  for  the 
same  conditions  that  favor  liberation  of  tissue  coagulins,  i.  e., 
much  laceration  and  destruction  of  the  tissue,  also  favor  the 
disintegration  of  leucocytes  by  offering  large  areas  of  surface 
for  contact.  Loeb  is  of  the  opinion,  however,  that  of  the  two, 
the  latter  factor  is  the  more  important.  It  may  be  recalled  that 
the  joint  action  of  tissue  and  blood  coagulins  is  greater  than  the 
sum  of  their  individual  actions,  which  also  must  be  an  important 
factor  in  causing  clotting  in  bleeding  wounds. 

As  to  the  relative  importance  of  stagnation  and  vessel  injury 
in  producing  thrombosis,  we  know  that  total  stasis  in  an  unin- 
jured vessel  may  not  result  in  thrombosis,  and,  on  the  other 
hand,  extensive  injury  or  large  calcified  plaques  in  the  intima 
of  the  aorta  may  also  cause  no  thrombosis  because  of  the  rapid- 
ity of  the  blood  flow  ;  and,  furthermore,  clotting  may  occur  even 
in  intact  vessels  under  the  influence  of  substances  liberating 
fibrin-ferment  in  the  blood ;  e.  g.,  snake  venoms,  nucleoproteid 
injections,  and  possibly  in  disease.  Presumably  clotting  does 
not  occur  when  the  stream  is  rapid,  because  any  fibrin-ferment 
that  may  be  liberated  by  injured  leucocytes  or  endothelium  is 
swept  away  before  fibrin  can  become  attached  to  the  vessel- wall. 
Naturally  the  combination  of  an  injured  vessel- wall,  a  slow  cur- 
rent, and  a  high  coagulability  offer  the  most  favorable  condi- 
tions, and  we  owe  to  Welch  the  appreciation  of  the  fact  that  in  a 
large  proportion  of  all  thrombi,  even  those  caused  by  apparently 
purely  mechanical  agencies  (e.  g.,  cardiac  incompetence),  bac- 
teria are  present  and  probably  determine  the  injury  to  the 
vessel-walls  and  the  liberation  of  fibrin-ferment.1  We  have 
previously  referred  to  L.  Loeb's  observations  on  the  effect  of 
bacteria  in  causing  coagulation  of  the  blood. 

Hyaline  thrombi  have  become  of  particular  interest  during 
the  past  few  years,  since  it  has  been  shown  that  they  are  fre- 
quently the  cause  of  extensive  degenerative  lesions  in  the  vis- 
cera, and  also  because  of  their  relation  to  the  more  recently 
understood  Jiemagglutinating  substances  (see  Chap.  ix).  Although 

1  Welch,  Venous  Thrombosis  in  Cardiac  Disease,  Trans.  Assoc.  Amer.  Phys., 
1900,  vol.  15. 


THROMBOSIS  271 

formed  of  red  corpuscles,  these  thrombi  do  not  stain  at  all  like 
normal  corpuscles,  presumably  because  a  certain  proportion  of 
the  hemoglobin  has  been  altered  or  lost  through  hemolysis.  Of 
particular  interest  is  their  reaction  to  Weigert's  fibrin  stain,  by 
which  they  often,  but  not  always,  stain  intensely ;  a  fact  that 
has  been  the  cause  of  much  confusion  in  earlier  studies.  Flex- 
ner 1  first  appreciated  the  nature  of  these  thrombi  as  origi- 
nating from  agglutinated  red  corpuscles,  although  Klebs,  Zieg- 
ler,  and  others  had  earlier  suggested  that  hyalin  thrombi  were 
formed  from  red  corpuscles.  Boxmeyer 2  independently  arrived 
at  the  same  conclusion  as  Flexner,  in  studying  hyalin  thrombi 
as  the  cause  of  necrosis  in  the  liver  of  animals  infected  with  the 
hog-cholera  bacillus.  Flexner  produced  hyalin  thrombi  by 
injecting  corpuscles  agglutinated  by  ricin,  or  by  injecting  ricin 
itself,  or  hemolytic  substances  such  as  ether  or  foreign  serum. 
As  the  thrombi  become  old,  the  corpuscles  lose  their  form  and 
color  and  produce  the  typical  hyalin  appearance.  Pearce3 
proved  conclusively  the  dependence  of  the  thrombus  formation 
upon  agglutination,  for  he  secured  the  same  results,  including 
the  liver  necrosis,  by  injecting  specific  agglutinating  serums. 
He  states  that  fibrin  threads  may  occasionally  be  found  at  the 
periphery  of  the  larger  thrombi,  but  never  in  the  smaller  ones. 
The  tendency  of  the  thrombi  to  stain  like  fibrin  by  Weigert's 
method  is  observed  particularly  when  the  tissues  have  been 
hardened  in  Zenker's  solution.  It  is  extremely  probable,  from 
Flexner's  observations,  that  in  the  thrombosis  produced  by 
injecting  various  toxic  substances  into  the  blood,  the  so-called 
"fibrin-ferment  thrombosis"  the  thrombi  are  merely  agglutina- 
tive thrombi,  devoid  of  fibrin ;  this  is  undoubtedly  true  for 
many  of  the  thrombi  observed  after  poisoning  with  the  pow- 
erfully agglutinative  snake  venoms  (see  Chap.  viii).  On 
the  other  hand,  some,  at  least,  of  the  hyalin  capillary  thrombi 
are  undoubtedly  composed  of  soft  masses  of  fibrin  which  have 
not  become  fibrillar,  although  the  successful  staining  by  fibrin 
stain  is  not  final  proof  of  the  fibrinous  nature  of  a  thrombus. 

Secondary  Changes  in  Thrombi. — The  changes  that 
occur  in  thrombi  after  they  have  existed  for  some  time  are  largely 
due  either  to  ingrowth  of  new  tissue  or  to  calcification,  the  latter 
of  which  will  be  considered  in  a  separate  chapter.  The 
only  other  change  of  interest  from  the  chemical  standpoint 
is  the  central  softening  which  may  occur  in  any  large  thrombus, 

1  Jour.  Med.  Research,  1902  (8),  316. 

2  Jour.  Med.  Research,  1903  (9),  146. 

3  Jour.  Med.  Research,  1904  (12),  329;  ibid.,  1906  (14),  541. 


272  DISTURBANCES  OF  CIRCULATION 

but  is  particularly  often  observed  in  the  large  globular  thrombi 
found  in  the  heart.  The  center  of  the  thrombus  may  be  so 
completely  softened  that  it  resembles  a  sac  of  pus,  the  contents, 
according  to  Welch,  consisting  of  uecrotic  fatty  leucocytes, 
albuminous  and  fatty  granules,  blood-pigment  and  altered  red 
corpuscles,  and  occasionally  acicular  crystals  of  fatty  acids. 
Undoubtedly  this  softening  is  related  to  the  process  of  fibrinol- 
ysis  previously  described,  and  depends  upon  digestion  of  the 
fibrin  by  leucocytic  enzymes ;  but  the  fact  that  the  central  por- 
tion alone  undergoes  softening  is  of  interest,  suggesting  that  the 
antibodies  for  leucocytic  proteoses,  which  Opie 1  found  present 
in  normal  serum,  prevent  digestion  at  the  surface  of  the  clot. 

EMBOLISM 

Emboli  offer  little  of  chemical  interest,  because  of  the  purely 
mechanical  nature  of  their  origin  and  of  the  effects  they  produce. 
An  exception  exists  in  the  case  of  fat  embolism,  for  the  manner 
in  which  the  fat  is  removed  from  the  blood  has  invited  con- 
siderable speculation.2  Part  of  the  fat  is  eliminated  in  the 
urine,  but  the  problem  of  how  it  escapes  from  the  glomerular 
capillaries  is  not  satisfactorily  explained  ;  large  emboli  undoubt- 
edly lead  to  rupture  of  the  capillary  walls,  and  probably  some 
fat  also  escapes  through  stomata  or  similar  intercellular  open- 
ings. Fat  may  also  escape  in  the  bile,  and  some  is  probably 
taken  up  by  the  tissue  and  endothelial  cells  by  phagocytosis. 
Beneke  found  that  the  fat  becomes  partly  emulsified  by  the 
mechanical  action  of  the  blood  current,  aided  to  a  slight  extent 
by  saponification.  The  larger  droplets  after  lodging  in  the 
capillaries  are  surrounded  by  leucocytes,  to  which  Beneke 
ascribes  an  active  part  in  the  removal  of  the  fat  as  fine  droplets 
by  phagocytic  action.  We  may  well  believe,  however,  that  the 
lipase  of  the  plasma  is  an  important  agent  in  disintegrating  the 
emboli,  although  its  action  is  limited  because  of  the  relatively 
small  surface  which  the  large  drops  offer  for  attack.  After  fat 
droplets  have  been  taken  into  the  cells,  they  presumbly  are 
utilized  in  metabolism  like  normally  acquired  fat,  as  described 
previously. 

Air  embolism  presents  some  features  of  interest  from  the 
chemical  standpoint,  especially  in  those  cases  following  sudden 
decrease  in  atmospheric  pressure  in  persons  who  have  been 
exposed  for  some  time  to  pressures  considerably  higher  than 

1  Jour.  Exper.  Med.,  1905  (7),  316. 

2  Full  discussion  by  Beneke,  Ziegler's  Beitr.,  1897  (22),  343. 


INFARCTION  273 

that  of  the  atmosphere  (diver's  palsy,  caisson  disease,  etc.).  This 
form  of  air  embolism  is  due  to  the  fact  that  fluids  can  dissolve 
much  more  gas  at  high  pressures  than  at  low  pressures ;  con- 
sequently when  the  abnormally  great  pressure  to  which  divers, 
caisson  workers,  etc.,  are  subjected  is  too  suddenly  reduced  to 
that  of  the  atmosphere,  the  excessive  gas  that  was  absorbed 
during  the  period  of  high  pressure  by  the  blood  and  tissue 
fluids  is  released,  and  forms  bubbles  in  the  tissues  and  blood. 
The  bubbles  in  the  nervous  tissues  may  cause  paralyses  of  vari- 
ous sorts,  or  death ;  those  in  the  blood  may,  if  in  sufficient 
amount,  cause  serious  or  fatal  capillary  obstruction.  The  bub- 
bles consist  chiefly  of  nitrogen,  because  the  power  of  the  blood 
to  hold  oxygen  in  combination  is  so  great  that  not  much  of  this 
gas  becomes  freed.1  Air  embolism  following  obstetrical  oper- 
ations or  surgical  operations  about  the  neck  and  chest  presents 
chiefly  mechanical  features,2  and  large  quantities  of  air  must  be 
present  to  cause  dangerous  obstruction  to  circulation.3  Gas- 
bubbles  may  be  produced  in  the  blood  soon  after  death  by  B. 
aerogenes  capsulatus,  but  it  is  not  probable  that  they  are  formed 
before  death  and  cause  air  embolism. 

INFARCTION 

The  changes  that  occur  in  infarcted  areas  are  of  much  interest 
in  connection  with  the  study  of  autolysis,  for  the  absorption  of 
the  necrotic  tissue  of  aseptic  infarcts  is  purely  a  matter  of  autol- 
ysis. Jacoby 4  found  by  ligating  off  a  portion  of  a  dog's  liver, 
and  keeping  the  dog  alive  for  some  time  afterward,  that  in  the 
infarcted  tissues  so  produced  leucin  and  tyrosin  could  be 
detected,  just  as  they  are  found  in  liver  tissue  undergoing  autol- 
ysis outside  of  the  body.  So,  too,  proteoses  may  appear  in  the 
urine  when  any  considerable  amount  of  tissue  is  cut  off  from 
its  blood-supply.  The  processes  of  autolysis  which  occur  in 
ordinary  sterile  iufarcts  are,  however,  extremely  slow,  and  it  is 
doubtful  if  enough  of  the  products  are  ever  in  the  blood  or 
urine  at  any  one  time  to  be  detected  or  to  cause  noticeable 
effects.  For  example,  in  an  infarct  of  the  kidney  which  was 
known  to  be  almost  exactly  fourteen  weeks  old,  there  still 
remained  a  layer  of  necrotic  cortex  one  millimeter  thick,  quite 
unabsorbed  during  this  time.  If  we  examine  such  aseptic 

1  This  subject  is  fully  discussed  by  Leonard  Hill  in   "Recent   Advances 
in  Physiology  and  Biochemistry,"  London,  1906. 

2  Review  of  literature  by  Wolff,  Virchow's  Archiv,  1903  (174),  454. 

3  See  Hare,  Amer.  Jour.  Med.  Sciences,  1902  (124),  843. 
*Zeit.  physiol.  Chem.,  1900  (30),  149. 

18 


274  DISTURBANCES  OF  CIRCULATION 

infarcts  in  various  stages,  we  get  the  impression  that  the  diges- 
tion is  accomplished  by  leucocytes  acting  on  the  periphery  of  the 
infarct,  and  not  entering  the  dead  area  deeply,  presumably 
because  of  a  lack  of  chemotactic  substances  in  the  dead  cells.  On 
the  other  hand,  it  seems  probable  that  the  tissue  enzymes  them- 
selves play  an  important  part  in  the  autolysis,  for  if  we  implant 
into  animals  pieces  of  tissue  in  which  the  enzymes  have  been 
destroyed  by  heating  to  boiling,  it  will  be  found  that  the  cells  and 
their  nuclei  remain  unaifeced  for  many  weeks ;  whereas  if  sterile 
unheated  pieces  of  tissue  in  which  the  enzymes  are  still  active  are 
implanted,  they  lose  their  nuclear  stain  and  begin  to  disintegrate 
relatively  soon,  without  apparent  participation  by  the  leucocytes.1 
Ribbert 2  found  that  in  experimentally  produced  anemic  infarcts 
in  the  kidney  of  rabbits  the  nuclei  retain  their  staining  property 
well  for  nearly  twenty-four  hours,  becoming  then  small  and 
deeply  stained,  undergoing  karyorrhexis,  and  in  large  part  disap- 
pearing from  the  convoluted  tubules  inside  of  forty-eight  hours, 
although  some  nuclei  may  persist  in  the  glomerules  for  three  or 
more  days.  In  human  infarcts,  Ribbert  believes,  the  process  goes 
on  faster,  for  he  has  observed  here  a  loss  of  nuclei  within  twenty- 
four  hours.  These  nuclear  changes  undoubtedly  depend  upon 
autolysis,  but  it  is  probable  that  the  enzymes  concerned  reside  in 
the  cytoplasm  rather  than  in  the  nucleus,  for  I  have  observed 
that  cells  of  lymphoid  type,  with  practically  no  cytoplasm,  gener- 
ally retain  their  nuclear  stain  much  longer  than  cells  with 
more  cytoplasm ;  this  is  particularly  noticeable  in  splenic 
infarcts,  where  the  Malpighian  corpuscles  retain  their  staining 
affinities  much  longer  than  the  pulp  elements.  Whether  the 
destruction  of  the  nuclei  is  accomplished  by  the  ordinary 
intracellular  proteases,  or  by  special  nucleoproteid-splitting 
enzymes  (nuclease,3  etc.),  remains  to  be  determined.  It  is  quite 
possible,  however,  that  the  first  changes  consist  of  a  splitting 
of  the  nucleoproteids  of  the  nucleus  by  the  autolytic  enzymes, 
liberating  the  nucleic  acid,  which  gives  the  nuclei  the  character- 
istic intense  staining  with  basic  dyes  (pycnosis)  observed  in 
areas  of  early  anemic  necrosis.  The  nucleic  acid  may  then  be 
further  decomposed  by  the  nuclease  or  similar  enzymes.  Taken 
altogether,  then,  it  would  seem  that  the  nuclear  and  cellular 
alterations  that  make  up  the  characteristic  picture  of  anemic 
necrosis  are  brought  about  by  the  intracellular  enzymes — an 
autolytic  process.  The  removal  of  the  dead  substance,  how- 

1  Wells,  Jour.  Med.  Eesearch,  1906  (15),  149. 

2  Virchow's  Arch.,  1899  (155),  201. 

3  Sachs,  Zeit.  physiol.  Chem.,  1905  (46),  337  ;  Schittenhelm,  ibid.,  354. 


INFARCTION  275 

ever,  seems  to  be  accomplished  rather  by  the  invading  leuco- 
cytes, through  heterolysis.  The  relatively  small  part  taken  by 
the  intracellular  enzymes  may  possibly  be  due  to  the  seeping 
through  them  of  alkaline  blood-plasma,  for  autolytic  enzymes 
are  not  active  in  an  alkaline  medium ;  the  leucocytic  enzymes, 
however,  act  best  in  an  alkaline  medium.1 

About  the  periphery  of  infarcts  is  usually  observed  more  or 
less  fat  formation  (Fischler  2),  particularly  in  the  endothelial 
cells  (Ribbert).  This  is  not  peculiar  to  infarcts,  however,  for 
Sata 3  found  a  similar  peripheral  fatty  metamorphosis  common 
to  all  necrotic  areas.  The  basis  of  this  is  probably  the  persist- 
ence of  the  cell  lipase,  which  acts  upon  fatty  acid  and  glycerin 
diffusing  into  the  necrotic  area  with  the  plasma,  unchecked  by 
the  normal  oxidative  destruction  of  these  substances.  (See 
"  Fatty  Degeneration,"  Chap,  xiv.) 

Hemorrhagic  infarcts  offer,  in  addition  to  the  changes  com- 
mon to  anemic  infarcts,  the  alterations  occurring  in  the  blood- 
corpuscles.  Panski4  found  that  after  ligation  of  the  splenic 
vein  of  dogs  the  red  corpuscles  begin  to  give  up  their  hemo- 
globin in  about  three  hours.  After  twelve  hours  fibrin  for- 
mation begins  in  the  tissues,  the  corpuscles  continue  to  give 
up  hemoglobin  and  become  cloudy  in  appearance.  Later,  iron- 
containing  pigment  is  formed  in  the  cells  beneath  the  capsule, 
but  in  the  deeper  tissue  even  the  iron  normally  present  in  the 
spleen  tissue  seems  to  disappear ;  this  probably  depends  upon 
the  fact  that  pigment  reacting  for  iron,  hemosiderin,  is  formed 
only  in  living  cells  under  the  influence  of  oxygen.  The 
hemolysis  is  probably  produced  either  by  the  action  of  autolytic 
products,  which  are  notoriously  hemolytic,  or  perhaps  also  by 
direct  attack  of  tissue  and  blood  proteases  upon  the  corpuscles. 

Other  retrogressive  changes  that  may  occur  in  infarcts,  such 
as  septic  softening  and  calcification,  are  not  greatly  different 
from  the  same  processes  occurring  in  other  conditions,  and  will 
be  considered  with  the  discussion  of  these  processes. 

1  More  fully  discussed  by  Wells,  loc.  cit. 

2  Cent.  f.  Path.,  1902  (13),  417. 

3  Ziegler's  Beitr.,  1900  (28),  461. 

4  "  Untersuchungen  iiber  den  Pigmentgehalt   der  Stauungsmilz,"  Dorpat, 
1890. 


CHAPTER    XII 


EDEMA1 

As  the  terra  edema  indicates  the  excessive  accumulation  of 
lymph  (which  may  be  either  normal  or  modified  in  composition) 
in  the  cells,  intracellular  spaces,  or  serous  cavities  of  the  body, 
the  problems  of  edema  are  inseparably  connected  with  the 
consideration  of  the  processes  of  physiological  formation  and 
removal  of  lymph.  For  many  years  the  study  of  these  processes 
has  been  a  favorite  field  of  investigation  by  physiologists,  and 
the  great  battle-place  of  the  "  vitalism  "  and  "  mechanism " 
schools  ;  and  to  this  day  the  forces  that  determine  the  formation 
of  lymph  and  its  subsequent  absorption  have  not  been  com- 
pletely understood.  By  the  application  of  the  principles  of 
physical  chemistry  to  the  problem,  however,  great  advances 
have  recently  been  made,  which  seem  to  render  our  understand- 
ing of  both  lymph-formation  and  its  pathological  accumulation 
in  the  tissues  much  clearer  and  more  nearly  accurate  than  they 
were  before.  We  shall  first  consider,  therefore,  the  physio- 
logical formation  of  lymph,  before  taking  up  the  subject  of 
edema. 

Composition  of  Lymph. — Lymph  consists  of  material  derived  from 
two  chief  sources.  The  greater  part  consists  of  fluid  passing  out  of  the 
capillaries  into  the  tissue-spaces ;  here  it  is  modified  by  the  addition  of 
products  of  metabolism  derived  from  the  tissue-cells,  and  by  the  sub- 
traction of  materials  that  the  cells  utilize  in  their  metabolism.  It  is, 
therefore,  essentially  a  modified  blood  plasma,  and  the  modifications  the 
plasma  undergoes  are  so  slight  that,  under  ordinary  conditions,  lymph 
shows  on  analysis  no  considerable  differences  from  blood  plasma,  except 
a  relative  poverty  in  proteids,  due  chiefly  to  the  impermeability  of  the 
capillary  walls  for  colloids.  Its  quantitative  composition  varies  greatly, 
depending  Upon  the  conditions  under  which  it  is  collected,  whether 
during  activity  or  rest,  etc.  The  following  tables  of  analyses  have  been 
collected  by  Hammarsten: 2 

1  A  complete  bibliography  is  given  by  Meltzer,  American  Medicine,  1904 
(8),  19  et  seq.,  and  references  will  be  given  below  only  when  referring  to 
special  points  or  to  articles  not  included  by  Meltzer.     Literature  also  reviewed 
by  Burton-Opitz,  Jour.  Amer.  Med.  Assoc.,  1899  (32),  51,  and  by  Ellinger, 
Ergebnisse  der  Physiol.,  1902  (I,  Abt.  1 ),  355. 

2  Physiological  Chemistry  ;  Amer.  translation,  1904,  p.  213. 

276 


FORMATION  OF  LYMPH  277 

1234 

Water 939.9  934.8  957.6  955.4 

Solids 60.1  65.2  42.4  44.6 

Fibrin 0.5  0.6  0.4  2.2 

Albumin 42.7  42.8  34.7) 

Fat,  cholesterin,  lecithin     .    .      3.8  9.2  .   .   \  35.0 

Extractive  bodies 5.7  4.4  .    .   j 

Salts ;    .      7.3  8.2  7.2  7.5 

1  and  2  are  analyses  of  lymph  from  the  thigh  of  a  woman,  3  is  from  the 
contents  of  sac-like  dilated  vessels  of  the  spermatic  cord,  4  is  lymph  from  the 
neck  of  a  colt. 

Chyle  differs  from  lymph  chiefly  in  the  presence  of  large  quantities  of 
fat ;  during  starvation  the  lymph  and  the  chyle  are  of  practically  the 
same  composition. 

Normal  lymph  contains  much  less  fibrinogen  than  does  the  blood 
plasma,  and  hence  coagulates  slowly.  Lipase  and  other  enzymes  have 
been  found  in  the  lymph,  as  in  the  plasma.  The  products  of  tissue 
metabolism  added  to  the  lymph  by  the  cells  may  render  it  toxic  (Asher 
and  Barbera1).  Under  pathological  conditions  the  lymph  may  be 
greatly  altered,  becoming  poorer  in  solids  under  some  conditions  of 
edema,  and  becoming  rich  in  proteids  and  blood-corpuscles  under  inflam- 
matory conditions,  until  it  partakes  of  the  characteristics  of  an  inflam- 
matory exudate  (see  analyses  of  transudates  and  exudates). 

FORMATION    OF    LYMPH2 

Filtration  Theory. — The  simplest  possible  conception  of 
lymph  formation  is  that  it  is  simply  the  result  of  filtration  of 
the  liquid  constituents  of  the  blood  through  the  capillary  walls 
under  the  influence  of  the  blood  pressure.  This  "filtration 
theory  "  was  supported  originally  by  Ludwig,  and  it  was  a  prom- 
inent factor  in  the  early  applications  of  mechanical  principles 
to  biological  processes.  In  support  of  this  theory  were  advanced 
the  results  of  numerous  experiments  in  which  it  was  shown  that 
increasing  the  blood  pressure  by  means  of  ligating  the  veins,  or 
by  causing  arterial  dilatation,  resulted  in  an  increase  of  the 
lymph  flowing  out  of  the  lymph-vessels  of  the  part.  The 
experimental  results  were  not  always  favorable  to  the  theory, 
however,  particularly  in  the  experiments  in  which  blood  pres- 
sure was  raised  by  arterial  dilatation  ;  often  the  flow  of  lymph 
was  little  increased,  even  when  the  arterial  flow  and  pressure 
were  greatly  increased.  Furthermore,  as  Leonard  Hill3  has 
urged,  there  is  reason  for  questioning  the  existence  of  such  a 
thing  as  a  "  filtration  pressure  "  in  organs  or  tissues  provided 
with  a  capsule,  since  within  this  capsule  all  structures  must  be 

1Zeit.  f.  Biol.,  1898  (36),  154. 

2  See  review  by  Asher,  Biochem.  Centralblatt,1905  (4),  1. 

3  Biochemical  Journal,  1906  (1),  55. 


278  EDEMA 

under  equal  pressure,  which  is  the  pressure  of  the  blood  ;  there- 
fore there  is  the  same  pressure  both  on  the  inside  and  on  the 
outside  of  the  capillary  walls.  Nevertheless,  the  filtration 
theory  held  for  many  years,  not  only  as  an  explanation  of  lymph 
formation,  but  also  as  an  explanation  of  urinary  secretion  and 
of  the  secretion  by  other  organs.  It  was  only  within  a  compar- 
atively short  time  that  it  became  clear  that  filtration  alone  could 
not  account  for  all  the  phenomena  of  secretion.  For  example, 
in  many  lower  forms  with  undeveloped  circulatory  systems,  and 
almost  no  blood  pressure,  secretion  goes  on  vigorously ;  the 
pressure  of  glandular  secretions  may  be  much  higher  than  the 
blood  pressure  within  the  capillaries ;  the  activity  of  secretion 
is  by  no  means  in  proportion  to  blood  pressure,  etc.  If  in 
glandular  secretion,  therefore,  fluids  are  removed  from  the  blood 
and  transferred  into  an  excretory  duct  through  the  action  of 
some  force  other  than  that  of  the  blood  pressure,  it  is  probable 
that  lymph  formation  is  equally  independent  of  blood  pressure. 
On  this  basis  Heidenhain  advanced  his — 

Secretory  theory  of  lymph  formation,  in  which  he  sug- 
gested that  lymph  is  the  product  of  an  active  secretion  by  the 
endothelial  cells  of  the  capillaries,  just  as  saliva  is  the  product 
of  the  activity  of  the  glandular  cells.  He  showed  that  certain 
chemical  substances  may  stimulate  lymph  flow,  independent  of 
blood  pressure,  just  as  pilocarpine  and  other  drugs  may  stimu- 
late the  secretion  of  saliva.  These  lymph-stimulating  sub- 
stances, which  he  named  lymphagogues,  fall  into  two  distinct 
classes.  One,  which  includes  such  substances  as  peptone,  leech 
extract,  strawberry  juice,  extracts  of  crayfish,  mussel  or  oysters, 
and  numerous  other  tissue  extracts,  are  characterized  by  causing 
the  secretion  of  a  lymph  which  is  rich  in  proteids,  even  richer 
in  proteids  than  the  blood  plasma ;  and,  furthermore,  there  is 
no  simultaneous  increase  in  urinary  secretion.  Heidenhain  con- 
sidered that  these  substances  caused  lymph  secretion  by  stimulat- 
ing the  capillary  endothelium  in  a  specific  manner ;  as  they 
caused  no  appreciable  rise  in  blood  pressure  the  increased  lymph 
secretion  certainly  could  not  be  attributed  to  filtration.  This 
independence  of  the  lymph  flow  on  blood  pressure  is  most  con- 
clusively shown  by  postmortem  lymph  secretion;  for  example, 
Mendel  and  Hooker  l  observed  lymph  flow  for  four  hours  after 
death,  in  a  dog  that  had  received  an  injection  of  peptone  eight 
minutes  before  being  killed. 

The  second  class  of  lymphagogues  includes  crystalloidal  sub- 
stances, such  as  sugar,  urea,  and  salts.  Lymph  secreted  under 
1  Amer.  Jour,  of  PhysioL,  1902  (7),  380. 


FORMATION  OF  LYMPH  279 

the  influence  of  these  substances  is  poorer  in  proteids  than  ordi- 
nary lymph,  and  at  the  same  time  an  increased  urinary  secretion 
is  produced.  With  these  crystalloidal  lymphagogues  the  amount 
of  effect  is  in  inverse  proportion  to  their  molecular  weight, 
which  means  that  their  effects  depend  upon  the  number  of 
molecules  in  solution  rather  than  upon  their  nature ;  in  other 
words,  the  stimulation  of  lymph  by  crystalloids  is  dependent 
upon  the  osmotic  pressure  of  the  crystalloids.  Heidenhain 
explained  their  action  as  follows  :  The  crystalloids  are  secreted 
into  the  lymph-spaces  by  the  action  of  the  capillary  endothelium, 
and  there,  owing  to  their  raising  osmotic  pressure,  cause  a  flowing 
of  water  out  of  the  vessels.  The  difficulty  here  is  to  explain  why 
the  crystalloids  while  still  in  the  vessels  do  not  attract  the  fluids 
from  the  lymph-spaces  into  the  blood,  and  so  cause  rather  a 
lessened  lymph  secretion. 

While  admitting  that  in  pathological  conditions  (e.  g.,  pas- 
sive congestion)  pressure  and  filtration  may  play  an  important 
part,  Heidenhain  considered  that  an  active  secretion  by  the 
endothelial  cells  is  the  chief  factor  in  the  normal  formation  of 
lymph.  The  means  by  which  the  cells  perform  this  function 
was  unknown;  it  was  considered  as  an  example  of  "vital  activ- 
ity/' Heidenhain  meaning  by  this  term  such  chemical  and 
physical  forces  of  living  cells  as  are  unknown  or  not  under- 
stood at  the  present  time,  rather  than  any  metaphysical  concep- 
tion of  living  matter,  such  as  many  vitalists  assume. 

Other  observers,  corroborating  Heidenhain' s  results  for  the 
most  part,  have  modified  or  amplified  his  theory.  Asher  and 
his  collaborators,  for  example,  ascribe  the  work  done  in  caus- 
ing lymph  formation  to  the  cells  of  the  various  tissues  and 
organs,  rather  than  to  those  of  the  capillary  wall.  The 
increased  flow  of  lymph  from  the  salivary  gland  that  occurs 
during  its  activity  they  consider  due  to  the  work  of  the  gland 
cells,  and  its  function  the  removal  of  products  of  metabolism. 
The  action  of  such  a  lymphagogue  as  peptone  they  ascribe  to 
its  stimulation  of  cellular  activity,  particularly  in  the  liver, 
where  it  causes  an  increased  formation  of  bile.  Gies1  and 
Asher  also  observed  that  after  injection  of  crystalloidal  lympha- 
gogues, such  as  sugar,  a  prolonged  flow  of  lymph  occurred 
after  the  death  of  the  animal,  proving  completely  that  such 
lymphagogic  action  is  independent  of  blood  pressure. 

Potocytosis, — In  explanation  of  the  process  by  which  the  cells, 
whether  endothelial  or  tissue-cells,  pass  fluids  through  themselves  from 

1  Amer.  Jour.  Physiol.,  1900  (3),  p.  xix;  Zeit.  f.  Biol.,  1900  (40),  207. 


280  EDEMA 

one  place  to  another,  Meltzer1  has  made  an  interesting  suggestion,  as 
follows  :  Considering  the  property  of  endothelial  cells  to  act  as  phago- 
cytes, MacCallum2  has  shown  that  solid  granules  (e.  g.,  coal  pigment, 
carmin)  are  taken  through  the  walls  of  the  lymphatics  by  the  phagocytic 
activity  of  their  endothelial  cells.  Meltzer  suggests  that  in  a  similar 
way  the  endothelial  cells  may  transport  through  the  vessel-walls  not  only 
solid  particles,  but  also,  by  the  same  mechanism,  substances  in  solution  ; 
and  for  this  hypothetical  process  he  suggests  the  name  ' ' potocytosis." 
There  can  be  little  question  that  cells  do  take  up  substances  in  solution, 
and  sometimes  this  is  done  in  an  apparently  selective  manner  ;  e.  g.,  the 
taking  up  of  bacterial  toxins  and  vegetable  poisons  in  the  peritoneal 
cavity  by  the  leucocytes.  Presumably  the  mechanism  of  "potocytosis" 
is  not  different  from  that  of  phagocytosis,  chemotactic  forces  determining 
the  occurrence  of  the  process.  No  experimental  evidence  has  been 
advanced  as  yet  for  this  very  plausible  hypothesis. 

Permeability  of  Capillaries. — In  explanation  of  the 
variability  in  the  amount  and  composition  of  the  lymph,  Star- 
ling 3  has  introduced  the  factor  of  altered  permeability  of  the 
capillary  walls,  which  presumably  depends  upon  the  number 
and  size  of  the  pores.  He  found  that  normally  the  lymph 
coming  from  the  lower  extremities  contains  only  2  per  cent,  to 
3  per  cent,  of  proteids,  while  lymph  from  the  intestines  con- 
tains 4  per  cent,  to  6  per  cent.,  and  lymph  from  the  liver  con- 
tains 6  per  cent,  to  8  per  cent,  of  proteids ;  hence  he  considers 
that  the  liver  capillaries  are  the  most  permeable,  i.  e.,  have  the 
largest  pores,  so  that  more  of  the  large  colloid  molecules  can 
escape  from  them.  The  effect  of  lymphagogues  of  the  first 
class  (peptones,  etc.)  he  attributes  to  their  poisonous  properties, 
and  the  consequent  injury  to,  and  alterations  in,  the  capillary 
wall.  The  crystalloidal  lymphagogues,  he  believes,  act  by  first 
attracting  fluids  from  the  tissues  into  the  blood  with  a  resulting 
"  hydremic  plethora,"  which  in  turn  leads  to  increased  blood 
pressure  and  consequent  filtration  of  a  watery  fluid  out  of  the 
vessels.  He  considers,  therefore,  that  the  amount  and  quality 
of  the  lymph  produced  in  any  part  are  determined  solely  by  two 
factors,  the  intracapillary  blood  pressure  and  the  permeability 
of  the  capillary  walls. 

In  connection  with  this  question  of  the  permeability  of  the 
capillary  walls,  Meltzer  suggests  that  the  contractility  and  irri- 
tability of  the  endothelium  may  be  a  potent  factor  in  deter- 
mining the  size  of  the  pores  in  the  capillary  walls.  When  in 
a  tonic  condition,  the  endothelium  is  firmly  contracted  about 
the  pores,  keeping  their  size  small ;  when  the  endothelial  cells 

1  Loc.  tit. 

2  Johns  Hopkins  Hosp.  Bull.,  1903  (14),  1. 

3  Lancet,  1896  (i),  May  9,  et  seq.;  Schiifer's  Text-book  of  Physiology,  vol.  1. 


FORMATION  OF  LYMPH  281 

become  relaxed  by  any  cause,  such  as  poisons,  high  blood  pres- 
sure, poor  nourishment,  etc.,  the  pores  are  enlarged,  and  in- 
creased escape  of  fluids  results.  It  must  be  borne  in  mind, 
however,  that  not  all  histologists  admit  that  capillary  walls  con- 
tain pores. 

Osmotic  Pressure. — Still  another  important  factor  in 
causing  fluid  to  leave  the  vessels  is  osmotic  pressure.  Heiden- 
hain  refers  to  this  cause  the  transudation  produced  by  crystal- 
loid lymphagogues,  although  in  a  rather  unsatisfactory  manner. 
As  a  result  of  the  more  recent  studies  of  physical  chemistry, 
and  its  application  to  biological  processes,  we  have  learned  to 
appreciate  the  importance  of  osmotic  pressure  in  cell  activi- 
ties (see  Introductory  Chapter),  and  in  the  question  of 
lymph  formation  it  occupies  a  particularly  important  place. 
We  may  consider  it  as  follows  :  In  the  blood  we  have  certain 
proportions  of  readily  diffusible  crystalloids  and  of  non- 
diffusible  colloids.  If  no  metabolic  processes  were  going  on  in 
the  tissues,  we  should  have  the  diffusible  substances  leaving  the 
vessel-walls  (leaving  out,  for  the  present,  any  question  of  activity 
on  the  part  of  the  endothelium)  until  an  osmotic  equilibrium 
is  established  in  the  tissues  and  in  the  blood.  As  a  matter  of 
fact,  however,  the  blood  proteids  are  not  absolutely  non-dif- 
fusible, but  small  quantities  do  pass  through  the  capillary  walls, 
and  so  lymph  under  such  a  hypothetical  condition  would  consist 
of  a  mixture  of  the  same  osmotic  concentration  as  the  blood 
plasma,  with  about  the  same  proportion  of  crystalloids,  but  a 
smaller  proportion  of  proteids ;  this,  it  will  be  noticed,  is  just 
about  the  composition  of  normal  lymph.  During  life,  however, 
the  cells  of  the  tissues  are  causing  metabolic  changes  in  these 
lymphatic  constituents,  and  these  changes  consist  chiefly  in 
breaking  down  large  molecules  of  proteids,  carbohydrates,  and 
fats  into  much  smaller  molecules.  Now  the  osmotic  pressure 
of  a  solution  is  dependent  upon  the  number  of  molecules  and 
ions  it  contains,  hence  by  breaking  down  these  few  large  mole- 
cules with  very  little  osmotic  pressure  into  many  small  mole- 
cules, the  osmotic  pressure  in  these  cells  and  tissues  becomes 
raised  above  that  of  the  blood-vessels,  and  consequently  water 
flows  out  of  the  vessels  because  of  the  increased  pressure.  We 
see  here  the  probable  explanation  of  the  stimulating  influence 
of  metabolic  products  upon  the  formation  of  lymph,  noted  by 
Hamburger,  Heidenhain,  and  others.  For  suggesting  and  urging 
the  importance  of  osmotic  pressure  in  the  formation  of  lymph 
we  are  indebted  particularly  to  Heidenhain,  v.  Koranyi,1  J. 
1  Zeit.  f.  klin.  Med.,  1897  (33),  1 ;  1898  (34),  1. 


282  EDEMA 

Loeb,1  and  Roth.2  Loeb  shows  very  clearly  the  relative  greatness 
of  the  water-driving  force  of  osmotic  pressure  as  compared  to 
that  of  blood  pressure,  by  his  statement  that  the  osmotic  pressure 
of  a  physiological  salt  solution  is  about  4.9  atmospheres,  which 
is  twenty  times  as  great  as  the  blood  pressure  with  which  we  have 
to  do  in  ordinary  physiological  experiments.  In  varying  osmotic 
conditions  we  may  readily  see  an  explanation  for  the  increased 
lymph  flow  that  occurs  during  tissue  activity ;  namely,  it  is  due 
to  the  increased  formation  of  metabolic  products.  Many  of  the 
lymphagogues  may  act  similarly  by  stimulating  metabolic  activ- 
ity, with  resulting  increase  in  the  formation  of  osmotic  pressure- 
raising  products  of  metabolism  in  the  organs  ;  e.  #.,  the  increased 
lymph  flow  from  the  thoracic  duct  that  follows  stimulation 
of  hepatic  activity  by  injection  of  peptone  (Heidenhain)  or 
ammonium  tartrate  (Asher  and  Busch  3).  As  we  shall  see  later 
in  considering  edema,  osmotic  pressure  plays  an  important  part 
in  the  pathological  formation  of  lymph. 

Summary. — We  see  from  the  above  discussion  that 
numerous  theories  have  been  advanced  to  explain  the  normal 
formation  of  lymph,  and  as  their  basis  exist  several  diiferent 
possible  factors.  Filtration,  active  secretion  by  the  capillary 
endothelium,  attraction  by  the  tissue-cells,  osmosis  in  response 
to  formation  of  crystalloids  outside  the  vessels ;  all  have  been 
shown  to  be  possible  causes  of  lymph  formation.  It  is  highly 
probable  that  in  a  certain  way  all  are  involved,  particularly  if 
we  accept  the  view  of  the  physical  school  that  "  secretion  "  and 
"  attraction  "  by  the  cells  are  merely  the  outcome  of  osmotic 
forces  ;  the  causes  of  lymph  formation  then  reduce  themselves 
to  two,  filtration  and  diffusion.  There  has  been,  until  recently, 
no  question  but  that  lymph  does  escape  from  the  vessels  through 
simple  filtration,  for  the  pressure  inside  the  capillaries  is  pre- 
sumably greater  than  outside,  the  capillary  walls  are  not  water- 
tight, and  they  are  not  impermeable  to  the  substances  dissolved 
in  the  plasma.4  Likewise  osmotic  exchanges  surely  go  on 
between  the  vessels  and  the  tissue-cells.  The  question  that 
remains  is,  do  these  two  factors  account  for  all  of  the  lymph 
formation,  and  are  they  sufficient  by  themselves  to  explain  the 

^finger's  Arch.,  1898  (71),  457. 

2Englemann's  Arch.,  1899,  p.  416. 

3  Zeit.  f.  Biol.,  1900  (40),  333. 

*Hill  ("Kecent  Advances  in  Physiology  and  Biochemistry,"  1906,  p.  618) 
disputes  the  possibility  of  such  a  thing  as  nitration  pressure,  on  the  ground 
that  the  structures  within  the  capsule  of  an  organ  must  all  be  alike  under  the 
influence  of  the  blood  pressure. 


ABSORPTION  OF  LYMPH  283 

physiological  regulation  and  the  pathological  variations  in  the 
lymph  flow  ?  They  are  purely  physical  or  mechanical  causes, 
and  the  '"  vitalist "  school  will  claim  that  they  are  inadequate  and 
that  "  vital  activities  "  of  the  cells  play  the  deciding  role.  But 
at  present  the  evidence  that  is  being  accumulated  seems  to  point 
more  and  more  strongly  to  the  conclusion  that  these  "  vital  activ- 
ities "  are  but  the  result  of  simple  well-known  physical  forces 
acting  under  very  complex  conditions — complex  because  of  the 
large  number  of  very  different  chemical  compounds  occurring 
together,  and  the  varying  influence  of  circulation,  food  supplies, 
cell  structure,  etc. 

ABSORPTION  OF   LYMPH 

By  no  means  all  the  fluid  that  escapes  from  the  vessels, 
nor  all  the  products  of  cell  metabolism  are  carried  away  in 
the  lymph — a  considerable  and  perhaps  the  greater  part  of  them 
is  absorbed  back  into  the  capillaries  directly.  A  classical  proof 
of  this  is  the  experiment  of  Magendie,  who  observed  that  if 
poisons  were  injected  into  the  leg  of  an  animal,  which  had  been 
separated  from  the  body  entirely  except  for  the  blood-vessels, 
that  poisoning  developed  in  the  usual  manner.  In  such  experi- 
ments the  lymph-vessels  are  severed  and  probably  largely 
occluded,  hence  it  does  not  solve  the  question  as  to  whether 
substances  are  absorbed  by  the  blood-vessels  under  normal  con- 
ditions. Orlow  found,  however,  that  during  absorption  of  fluid 
from  the  peritoneal  cavity  there  is  no  perceptible  increase  in  the 
lymph  flow  from  the  thoracic  duct.  Addition  of  sodium  fluoride, 
a  protoplasmic  poison,  was  found  to  interfere  with  this  absorp- 
tion, for  which  and  other  reasons  Heidenhain  and  Orlow  con- 
sidered that  the  absorption  depended  upon  the  "  vital  activity  " 
of  the  cells.  More  nearly  reproducing  normal  conditions  were 
the  experiments  of  Starling  and  Tubby,  who  found  that 
methylene-blue  or  indigo-carmine  injected  into  the  pleura  or 
peritoneum  appeared  in  the  urine  long  before  it  colored  the 
lymph  in  the  thoracic  duct.1  Adler  and  Meltzer  found  evidence, 
however,  that  not  all  the  absorption  is  accomplished  by  the 
blood-vessels,  for  obstruction  of  the  thoracic  duct  retards  absorp- 
tion. That  the  absorption  is  not  dependent  solely  upon  the 
circulation  and  blood  pressure  is  shown  by  the  fact  that  absorp- 
tion from  the  peritoneal  cavity  occurs  in  dead  bodies  (Ham- 
burger, Adler  and  Meltzer). 

The  nature  of  the  mechanism  by  which  fluids  are  taken  into 

1  See  Mendel,  Amer.  Jour.  Physiol.,  1899  (2),  342. 


284  EDEMA 

the  blood-vessels  is  still  unknown.  We  can  easily  understand  the 
entrance  of  injected  poisons  and  coloring- matters  from  the  tissues 
into  the  blood,  because  they  are  more  concentrated  at  the  point 
of  injection  than  in  the  blood,  hence  they  may  diifuse  directly 
through  the  capillary  wall.  Likewise  we  can  understand  the 
diffusion  of  water  from  a  hypotonic  solution  into  the  blood,  but 
how  a  solution  of  the  same  concentration  as  that  of  the  blood 
can  enter  the  blood  is  difficult  to  explain.  Cohnstein  and  also 
Starling  attribute  this  absorption  to  the  proteids  of  the  blood 
in  the  following  manner  :  After  a  fluid  is  injected  into  the 
tissues  or  serous  cavities  there  occurs  a  diffusion  exchange  be- 
tween this  fluid  and  the  blood,  until  the  concentration  of  the 
crystalloids  in  each  is  equal ;  but  the  proteids  of  the  blood  can- 
not diffuse,  and  as  they  exert  a  positive  although  very  slight 
osmotic  pressure,  this  difference  in  osmotic  pressure  in  favor  of 
the  blood  causes  diffusion  of  the  extravascular  fluid  into  the 
blood.  Roth  has  also  applied  this  idea  in  a  rather  complicated 
manner  to  the  absorption  occurring  in  metabolic  processes  (see 
Meltzer),  but  it  must  be  admitted  that  it  is  an  unsatisfactory 
solution  of  the  problem. 

Passage  of  the  fluid  from  the  tissues  into  the  lymph  stream 
was  very  easy  to  understand  in  the  light  of  the  older  conception 
of  the  lymphatic  circulation,  namely,  that  the  lymph-vessels 
were  merely  continuations  of  the  interstitial  spaces;  we  could 
then  assume  that  as  soon  as  the  fluid  left  the  blood-vessels  it 
was  practically  within  the  lymphatic  system,  and  was  crowded 
along  the  lymphatic  channels  by  the  vis  a  tergo,  aided  by  the 
valves  of  the  lymph- vessels  and  the  intrathoracic  vacuum.  But 
it  now  seems,  particularly  through  the  studies  of  MacCallum,1 
that  the  lymphatic  vessels  form  a  closed  system,  not  in  com- 
munication with  the  interstitial  spaces.  This  being  the  case, 
we  have  to  explain  the  passage  of  the  lymph  through  the  walls 
of  the  lymphatic  vessels,  and  this  is  a  problem  which  is  not  by 
any  means  a  simple  one,  and  which  has  yet  to  be  investigated. 

THE  CAUSES  OF  EDEMA 

With  the  facts  and  hypotheses  mentioned  in  the  preceding 
paragraphs  in  mind,  we  may  consider  their  bearing  on  the  pro- 
duction of  abnormally  large  accumulations  of  lymph  in  the  tis- 
sues, that  is,  edema.  We  can  imagine  any  one  of  the  following 
factors  as  causing  or  helping  to  cause  such  a  pathological  accum- 
ulation : 

1  Johns  Hopkins  Hosp.  Bull.,  1903  (14),  1. 


THE  CAUSES  OF  EDEMA  285 

1.  Obstruction  to  outflow  through  the  lymph- vessels. 

2.  Increased  blood  pressure. 

3.  Decreased  extravascular  pressure. 

4.  Increased  permeability  of  the  capillary  walls. 

5.  Increased  filterability  of  the  blood  plasma. 

6.  Osmotic  pressure  changes — either  an  extravascular  in- 

crease or  an  intravascular  decrease. 

These  may  be  taken  up  one  by  one,  and  considered  in  relation 
to  their  bearing  upon  the  general  problem  of  edema. 

1.  Obstruction  to  Outflow  through  the  I/ymph- 
vessels. — Because  of  the  very  abundant  anastomosis  of  the 
lymphatic  vessels  it  is  extremely  difficult  or  impossible  to  cause 
any  appreciable  obstruction  to  the  lymphatic  circulation  by  liga- 
tion  of  lymphatic  trunks  in  the  limbs  or  organs  of  the  body, 
and  in  pathological  conditions  this  possible  cause  of  edema  is 
seldom  actually  observed.  The  chief  instance  of  edema  from 
lymphatic  obstruction  is  observed  after  occlusion  of  the  thoracic 
duct  by  tumors,  tuberculous  processes,  animal  parasites,  or 
thrombosis ;  such  occlusion  is  usually  followed  by  rupture  of 
the  duct  or  its  tributaries,  with  the  production  of  chylous  ascites 
or  chylothorax,  and  chyluria.  Filaria  or  their  ova  may  occupy 
so  many  of  the  lymphatic  channels  of  an  extremity  (leg)  or  part 
(scrotum)  that  the  anastomotic  channels  are  thoroughly  blocked, 
with  a  resulting  local  edema  that  in  course  of  time  is  followed 
by  the  production  of  inflammatory  connective  tissue  and  ele- 
phantiasis.1 Chronic  lymphangitis  may  also  result  in  lymphatic 
obstruction  to  such  an  extent  that  chronic  edema  results. 

Another  way  in  which  edema  may  be  caused  or  influenced  by 
lymphatic  obstruction  is  generally  overlooked,  but  it  is  possibly 
of  great  importance ;  namely,  from  pressure  upon  the  lymph 
channels  by  dilated  vessels  in  hyperemia,  or  by  cellular  exu- 
dates  and  swollen  tissues  in  inflammation.  We  see  evidence 
of  this  in  the  rapid  absorption  of  exudates  that  frequently  fol- 
lows the  removal  of  but  a  part  of  the  fluid  in  a  chest  cavity ; 
apparently  the  decrease  in  pressure  frees  the  paths  of  absorption 
and  permits  them  to  take  up  the  remaining  fluid.  In  inflam- 
matory edema  the  lymphatic  obstruction  is  probably  not  great, 
for  Lassar  found  that  the  amount  of  lymph  escaping  from  an 
edematous  extremity  is  much  greater  than  from  a  normal  one ; 
but  in  the  case  of  strangulated  hernias  or  other  conditions  in 
which  edema  results  from  circular  constriction,  obstruction  of 
the  lymphatic  vessels  may  be  a  factor  of  no  mean  importance. 

There  is  no  difficulty  in  understanding  edema  from  the  above 
1  Hanson,  Allbutt's  System,  1897  (ii),  1082. 


286  EDEMA 

causes — it  is  simply  a  passive  congestion  of  the  lymphatic  cir- 
culation, and  no  chemical  factors  are  involved.  The  nature  of 
the  fluid  found  in  such  forms  of  edema  will  be  discussed  later. 

2.  Increased  Blood  Pressure. — This  takes  us  back  to 
the  filtration  theory  of  lymph  formation,  and  as  it  is  generally 
conceded  that  more  or  less  fluid  escapes  from  the  vessels  by  this 
mechanical  process,  the  questions  to  be  decided  are :  Can  and 
does  increased  blood  pressure,  alone  and  without  other  aiding 
factors,  cause  edema?  If  not,  does  it  play  an  auxiliary  part 
in  producing  edema,  and  how  important  a  part  may  this  be  ? 
Many  experiments  have  been  performed  with  the  object  of 
answering  these  questions,  with  more  or  less  conflicting  results. 
Cohnheim  demonstrated  that  vasodilation  (active  hyperemia) 
alone  will  never  bring  on  an  edema  ;  and  many  observers  state 
that  ligation  of  the  femoral  or  other  large  veins  will  not  cause 
edema  in  animals.  However,  when  the  vein  is  occluded,  and 
the  arteries  are  dilated  by  cutting  their  vasoconstrictor  nerves, 
then  edema  may  result  (Ranvier,  Cohnheim) ;  but  whenever 
venous  outflow  is  impeded,  we  have  other  factors  than  simply 
increased  pressure  to  consider,  for  the  nourishment  of  the  parts 
is  decidedly  impaired,  and,  as  we  shall  see  later,  this  may  be  of 
much  greater  importance  than  is  the  associated  rise  in  blood 
pressure.  To  produce  edema  in  the  lungs  by  mechanical  forces 
it  is  necessary  to  ligate  the  aorta  and  its  branches,  or  the  pul- 
monary veins  (Welch).  As  such  high  pressures  do  not  occur 
in  any  pathological  conditions,  it  is  safe  to  assume  that  increased 
pressure  alone  is  not  capable  of  causing  by  itself  the  pulmonary 
edema  so  frequently  observed  clinically.  Welch,1  however,  has 
supported  the  hypothesis  that  a  disproportion  between  the 
working  power  of  the  left  ventricle  and  of  the  right  ventricle 
may  lead  to  pulmonary  edema  through  pulmonary  hyperemia. 
In  the  edema  of  passive  congestion  generally,  increased  blood 
pressure  would  seem  to  be  an  important  factor,  and  there  is  no 
doubt  that  with  an  increased  pressure  of  the  degree  observed  in 
such  conditions  some  increase  in  the  lymph  flow  would  result ; 
but  from  the  evidence  at  hand  it  is  improbable  that  the  amount 
of  lymph  so  secreted  would  ever  be  more  than  the  lymph-vessels 
could  carry  away.  Even  the  added  obstruction  to  lymphatic 
flow  due  to  pressure  upon  the  lymph  capillaries  by  congested 
blood-vessels,  and  the  resistance  to  the  lymph  escaping  from  the 
thoracic  duct  offered  by  the  increased  pressure  in  the  subclavian 
vein,  would  not  satisfactorily  account  for  the  edema  of  cardiac 
incompetence.  Not  to  go  into  details  here,  it  may  be  stated  that 
1  Virchow's  Arch.,  1878  (72),  375;  see  also  Meltzer  (loc.  cit.}. 


THE  CAUSES  OF  EDEMA  287 

the  impression  is  growing  that  uncomplicated  rise  in  blood 
pressure  is  not  sufficient  by  itself  to  produce  edema.  Some  of 
the  reasons  for  belittling  this  factor  will  be  brought  out  in  the 
subsequent  discussion. 

3.  Decreased  Extravascular  Pressure. — This  factor 
is  particularly  prominent  in  the  so-called  "  edema  ex  vacuo" 
which  occurs  after  the  absorption  of  an  area  of  tissue  which  is 
so  located  that  the  surrounding  tissues  cannot  contract  or  fall 
in  to  fill  the  gap,  e.  g.,  brain  softening,  serous  atrophy  of  fat. 
A  still  better  example,  however,  is  the  edema  that  follows  local 
decrease  in    atmospheric    pressure    in    "  cupping."       In    these 
instances  the  edema  depends  partly  upon  increased  transudation, 
and  partly  on  the  retention  of  the  fluid  in  the  tissues,  because 
it  cannot  well  leave  them  against   the   atmospheric   pressure. 
The  idea  advanced  by  Landerer  that  decreased  elasticity  of  the 
tissues  was  a  possible  cause  of  edema  has  been  disproved  by 
Bonniger,1  who  found  but  little  alteration  in  the  elasticity  of 
tissues  the  seat  of  edema.       Edema  ex  vacuo  is  again  an  illus- 
tration of  edema  due  to  purely  mechanical  causes,  but  it  is  of 
little  practical  importance. 

4.  Increased  Permeability  of  the  Capillary  Walls. 
— The  importance  of  this  factor  in  the  production  of  edema  was 
first  demonstrated  by  Cohnheim  and  Lichtheim,  who  found  that 
the  production  of  an  enormous  increase  in  the  amount  of  fluid 
in  the  blood  (hydrernic  plethora)  by  injecting  large  quantities  of 
salt  solution,  caused  an  edema  of  the  viscera  and  serous  cavities, 
but  not  any  subcutaneous  edema  until  the  skin  had  been  irritated 
by  some  means,  such  as  hot  water,  iodin,  etc.     By  this  irrita- 
tion the  capillary  walls  are  injured,  and  an  excessive  escape  of 
the  blood  fluids  follows.      Magnus  also  showed  that  poisoning 
with  arsenic,  which  injures  the  vessels,  favored  the  experimental 
production  of  edema  by  transfusion.     Starling,  as  noted  before, 
observed  that  the  permeability  of  the  capillaries  varies  normally 
in  different  organs  and  tissues,  which  determines  quantitative 
and    qualitative    differences   in    the    lymph    normally    flowing 
from  various  vascular   areas.       Heidenhain's    "  lymphagogues 
of  the  first  class,"  which  are  all  poisonous  substances,  prob- 
ably act  by  increasing  the  permeability  of  the  capillaries,  and 
in    this    way    they    produce    local   urticaria,    which    is    often 
observed  as  a  result  of  poisoning  by  these  same  lymphagogues, 
e.  g,,  shellfish  and  strawberry  poisoning.     Just  what  changes 
are  produced  in  the  capillary  walls  that  renders  them  more  per- 
meable we  do  not  know.     Possibly  in  some  instances  it  is  a 

1Zeit.  exp.  Path.  u.  Ther.,  1905  (1),  163. 


288  EDEMA 

partial  solution  of  the  intracellular  cement  substances,  possibly 
an  enlargement  of  the  stomata  through  loss  of  tonicity  of  the 
endothelium  (Meltzer),  sometimes  it  may  be  actual  death  of  the 
endothelial  cells,  or,  as  Heidenhain  and  Cohnheim  thought,  it 
may  be  a  stimulation  of  the  endothelial  cells  to  increased 
secretory  activity. 

Under  pathological  conditions  increased  permeability  of  the 
capillary  walls  is  probably  one  of  the  chief  factors  in  the  pro- 
duction of  certain  forms  of  edema.  We  see  evidence  of  it 
particularly  in  inflammatory  edema,  with  its  proteid-rich  ex- 
udate.  It  cannot  be  doubted  that  in  such  conditions  actual 
physical  alterations  take  place  in  the  capillaries,  when  we  see 
that  the  slightly  diffusible  proteids  escape  from  the  vessels  in 
the  same  proportions  as  they  exist  in  the  plasma  ;  there  can  be 
here  no  question  of  heightened  cell  activity  or  increase  in 
osmotic  pressure,  especially  not  when  we  note  the  indistinguish- 
able transition  of  such  an  inflammatory  exudate  into  one  con- 
taining leucocytes  and  red  corpuscles,  which  must  pass  through 
openings  of  some  kind  in  the  vessels.  Edema  due  to  inflam- 
mation and  poisoning  certainly  depends  to  a  large  degree  upon 
alterations  in  the  vessel- walls.  The  question  remaining  is,  do 
edemas  that  are  not  associated  with  distinct  inflammatory  or 
toxic  influences  depend  also  upon  the  vascular  permeability  ? — 
does  increased  permeability  ever  lead  to  the  formation  of  proteid- 
poor  transudates  ?  Cohnheim  was  inclined  to  attribute  nearly 
all  edema  to  this  cause,  for  in  passive  congestion,  or  nephritis, 
or  any  of  the  common  causes  of  edema,  it  is  easy  to  find  reason 
for  the  belief  that  poisons  may  be  present  in  the  blood ;  and  as 
there  was  good  evidence  that  the  blood  pressure  alone  could  not 
account  for  the  edema,  it  was  natural  to  ascribe  all  these  forms 
of  edema  to  the  action  of  toxic  substances  upon  the  capillary 
walls,  leading  to  increased  permeability  ;  or,  whatimight  amount 
to  the  same  thing,  increased  secretory  activity  of  the  endothe- 
lium, as  understood  by  Heidenhain,  It  is  impossible  at  this 
time  to  eliminate  as  non-existent  this  secretory-activity  doctrine, 
but,  as  we  hope  to  show  later,  there  exist  other  factors  in  all 
these  non-inflammatory  edemas  that  are  sufficient  to  account  for 
the  edema  without  our  having  recourse  to  this  hypothesis.  For 
the  present,  therefore,  we  may  consider  altered  capillary  perme- 
ability as  an  essential  factor  in  edemas  characterized  by 
proteid-rich  fluids  (exudates),  and  state  that  the  influence  of 
altered  permeability  in  the  production  of  proteid-poor  fluids 
(transudates)  is  not  proved,  and  is  perhaps  not  of  impor- 
tance. 


THE  CA  USES  OF  EDEMA  289 

5.  Increased  Filterability  of  the  Blood  Plasma. — 

This  takes  us  back  to  Richard  Bright7 s  conception  of  renal 
dropsy.  He  imagined  that  through  the  great  loss  of  albumin 
in  the  urine  the  blood  became  so  thinned  and  watery  that  it 
could  filter  through  the  vessel-walls,  while  normal  plasma,  he 
thought,  was  too  thick  and  viscid  to  do  so.  The  same  idea  was 
applied  to  the  edemas  of  cachexia  in  cancer,  etc.,  chlorosis,  and 
all  forms  of  edema  associated  with  a  decrease  in  the  corpuscular 
or  proteid  elements  of  the  blood.  With  our  present  knowledge 
of  diffusion  of  crystalloids  and  colloids  we  can  readily  appreci- 
ate that  a  decrease  in  the  blood  colloids,  such  as  might  occur  in 
these  diseases,  could  not  modify  the  passage  of  fluids  through 
the  capillary  walls  to  any  considerable  degree.  Stewart  and 
Bartels  considered  that  in  renal  dropsy  the  increased  filterability 
of  the  plasma  was  not  due  so  much  to  the  loss  in  albumin  as  to 
retention  of  water,  which  caused  an  hydremic  plethora.  But 
this  factor  was  soon  eliminated,  for  it  was  found  that  complete 
anuria,  produced  by  ligating  both  ureters,  does  not  cause  edema  ; 
and  also  that  to  produce  an  edema  by  increasing  the  water  of 
the  blood  it  was  necessary  to  increase  it  many  times  as  much  as 
it  can  ever  be  increased  by  disease.  Simply  increasing  the 
proportion  of  water  by  removing  part  of  the  blood  and  inject- 
ing a  corresponding  amount  of  salt  solution  did  not  cause 
edema  (Cohnheim  and  Lichtheim).  We  may,  therefore,  look 
upon  the  hypothesis  of  increased  filterability  of  the  blood  as 
chiefly  of  historic  interest,  and  not  an  important  factor  in  the 
causation  of  edema. 

6.  Disparity  of  Osmotic  Pressure  in  Favor  of  the 
Tissues  and  I/ymph  over  the  Blood. — On  a  preceding 
page  we  have  already  considered  the  means  by  which  changes 
in  osmotic  pressure  in  the  tissues  are  brought  about,  and  how 
they  may  lead  to  an  accumulation  of  fluid.     The  importance  of 
osmotic  pressure  in  causing  pathological  edema  was  suggested 
by  Loeb  1  in  his  studies  on  the  physiological  action  of  ions. 
He  stated  that  edema  occurred  when  the  osmotic  pressure  was 
higher  in  the  tissues  than  it  was  in  the  blood  and  lymph,  and 
the  cause  was  to  be  sought  in  conditions  that  lowered  the  osmotic 
pressure  of  the  blood  and  lymph  or  raised  that  of  the  tissues. 
This  condition  he  found  in  the  accumulation  of  metabolic  prod- 
ucts : — in  the  case  of  muscle,  tetanization  of  a  frog's  muscle 
for  ten  minutes  raised  the  osmotic  pressure  over  one  atmosphere; 
separating  a  muscle  from  its  blood-supply  led  to  such  an  increase 
in  osmotic  pressure  that  it  took  up  water  from  a  4.9  per  cent. 

1  Pfliiger's  Arch.,  1898  (71),  457. 
19 


290  EDEMA 

NaCl  solution,  which  has  a  pressure  of  over  thirty  atmospheres. 
When  we  consider  that  in  his  studies  on  lung  edema  Welch 
was  able  by  ligation  of  the  aorta  to  raise  the  blood  pressure 
less  than  ^_  atmosphere,  we  begin  to  appreciate  how  much  more 
powerful  are  the  forces  of  osmotic  pressure  that  are  at  work  in 
the  body  than  is  the  blood  pressure,  even  of  the  aorta  itself. 

Loeb  found  that  whenever  oxidation  is  impaired  in  a  tissue  its 
osmotic  pressure  rises,  due  to  the  accumulation  of  incompletely 
oxidized  metabolic  products,  particularly  acids,  and  as  a  result  the 
muscle  takes  up  water  and  becomes  edematous.  On  this  basis 
we  may  explain  the  edema  of  venous  stagnation  as  due  to  accu- 
mulation of  products  of  metabolism,  partly  because  of  impaired 
oxidation,  partly,  perhaps,  because  of  their  slow  removal  in  the 
blood  on  account  of  the  circulatory  disturbance.  The  so-called 
"neurotic"  edemas  may  possibly  be  explained  by  local  increase 
in  metabolic  activity  brought  about  by  nervous  stimuli,  which 
causes  increased  formation  of  substances  raising  osmotic  pressure 
in  the  stimulated  tissues.  In  renal  edema  the  retention  of  water 
also  seems  to  depend  rather  on  osmotic  pressure  than  on  cir- 
culatory disturbances  or  alterations  in  the  vessel-walls,  for  it 
has  been  shown  that  retention  of  chlorides,  which  the  diseased 
kidneys  do  not  eliminate  normally,  is  an  important  cause  of  the 
dropsy.  The  chlorides  accumulating  in  the  tissues  lead  to  an 
increased  osmotic  pressure,  which  causes  the  abstraction  of  water 
from  the  blood  and  its  retention  in  the  tissues.  (The  details  of 
this  subject  will  be  considered  later.)  Conversely,  Meltzer  and 
Salant  found  that  salt  solution  is  absorbed  from  the  peritoneal 
cavity  more  rapidly  in  nephrectonized  rabbits  than  in  normal 
rabbits,  because  metabolic  products  accumulate  in  the  blood  and 
raise  its  osmotic  pressure  above  normal. 

There  are  some  difficulties,  however,  in  applying  the  influence 
of  osmotic  pressure  as  an  explanation  of  all  edemas.  For 
example,  in  edema  of  the  lungs,  as  Meltzer  points  out,  what  is 
the  force  that  drives  the  fluid  into  the  empty  air-cells?  Equally 
difficult  to  explain  as  the  result  of  osmotic  disturbance  is  the 
distribution  of  fluid  that  is  seen  in  cardiac  dropsy.  The  fluid 
does  not  accumulate  in  the  tissues  where  metabolism  is  greatest, 
or  where  the  most  oxygen  is  used;  but  rather  in  the  inactive 
subcutaneous  tissues  and  in  the  serous  cavities.  Possibly  the 
original  trans udation  does  occur  in  the  muscles  and  solid 
viscera,  and  the  fluid  is  then  mechanically  forced  out  of  them 
into  the  surrounding  tissue-spaces,  later  settling  according  to 
the  laws  of  gravity  or  according  to  the  distensibility  of  the 
tissues. 


SPECIAL  CAUSES  OF  EDEMA  291 

Summary. — We  find  that  a  number  of  factors  may  be 
considered  as  responsible  for  edema,  some  of  them  being  promi- 
nent in  one  instance,  some  in  another,  but  in  few  cases  can  we 
consider  one  factor  alone  as  the  sole  cause.  In  most  of  the  forms 
of  edema,  such  as  those  due  to  renal  disease  and  cardiac  disease, 
it  now  seems  probable  that  osmotic  pressure  changes  play  the 
most  important  part ;  whereas  in  inflammatory  edema  there  can 
be  no  question  that  alteration  in  the  capillary  walls  is  the  most 
essential  factor.  But  the  mechanical  factor  of  blood  pressure 
cannot  be  disregarded,  although  by  itself  seldom  sufficient  to  cause 
edema ;  associated  with  other  factors  it  is  undoubtedly  an 
important  agency,  for  there  are  few  edemas  that  are  not  asso- 
ciated with  increased  blood  pressure.  Hydremia  and  hydremic 
plethora  may  almost  be  disregarded,  except  in  so  far  as  they 
may  cause  altered  metabolism  in  the  tissues,  injury  to  vessel- 
walls,  and  decreased  osmotic  pressure  within  the  vessels. 
Lymphatic  obstruction  is  possibly  a  factor  of  some  secondary 
importance  if  we  consider  that  distended  vessels  and  tense 
tissues  may  occlude  the  lymph  capillaries. 


SPECIAL  CAUSES  OF   EDEMA 

We  may  now  consider  which  of  the  above  factors  are  at  work 
in  bringing  about  edema  under  the  conditions  in  which  it  is 
usually  observed  clinically. 

"  Cardiac  "  I$dema. — Passive  congestion  introduces  nearly 
all  these  factors,  for  in  addition  to  the  increased  blood  pres- 
sure there  is  also  an  opportunity  for  changes  in  the  capillary 
wall,  either  from  stretching  and  thinning  of  the  cells  and  cement 
substances,  or  from  "  loss  of  tone"  in  the  endothelium  surround- 
ing the  stomata  (Meltzer),  or  from  toxic  injury  by  accumulated 
products  of  tissue  metabolism.  When  the  stasis  is  nearly  com- 
plete, or  if  it  is  complete  for  a  time  and  then  relieved,  the 
endothelium  may  be  injured  through  lack  of  nourishment.  As 
the  edematous  fluid  in  passive  congestion  is  usually  of  a  watery 
type,  poor  in  proteids,  the  edema  is  probably  less  dependent  upon 
capillary  permeability  than  upon  other  factors,  except  in  the  case 
of  acute  stasis,  when  the  fluid  partakes  of  the  character  of  the 
exudates.  Undoubtedly  the  accumulation  of  crystalloids  within 
the  tissues  also  plays  a  most  important  part  in  this  form  of 
edema,  Loeb's  experiments  having  shown  how  greatly  osmotic 
pressure  is  raised  in  tissues  having  deficient  oxygen  supply. 
Finally,  there  is  probably  more  or  less  obstruction  to  lymphatic 
outflow  because  of  the  increased  pressure  upon  the  lymphatic 


292  EDEMA 

channels,  and  perhaps  also,  in  the  case  of  cardiac  incompetence, 
obstruction  to  the  discharge  of  lymph  from  the  thoracic  duct 
into  the  subclavian  vein  against  the  high  intravenous  pressure. 

Renal  Edema. — We  must  recognize  under  this  heading 
two  different  types  of  edema.  In  acute  nephritis  (e.  g.,  in 
scarlatina)  toxic  materials  appear  to  be  the  chief  cause,  and,  as 
Senator  contends,  injure  alike  the  capillaries  of  the  renal  glom- 
erules  and  of  the  subcutaneous  tissues  ;  in  each  case  there  results 
an  increased  permeability  which  is  manifested  by  albumin uria 
as  a  result  of  the  injury  to  the  renal  capillaries,  and  by  edema 
as  a  result  of  the  injury  to  the  tissue  capillaries.  This  sort  of 
edema  is  allied  to  that  produced  by  peptone  and  similar  lympha- 
gogues,  and  we  might  well  imagine  that  the  mechanism  con- 
sisted merely  in  an  injury  to  the  capillaries  through  which 
excessive  fluid  is  driven  by  the  blood  pressure,  were  it  not  for 
such  observations  as  those  of  Mendel  and  Hooker,1  who  found 
that  postmortem  flow  is  increased  by  these  lymphagogues  also. 
We  can  hardly  account  for  the  force  exhibited  in  postmortem 
lymph  flow  on  any  other  ground  than  that  it  is  furnished  by 
osmotic  pressure,  unless  we  wish  to  fall  back  upon  "  vital  activ- 
ity" of  the  surviving  cells.  Hence  it  is  probable  that  even  in 
the  edemas  of  toxic  conditions,  such  as  acute  nephritis,  osmotic 
pressure  plays  a  part,  the  pressure-raising  substances  probably 
being  abnormal  or  excessive  metabolic  products  of  the  cells 
affected  by  the  poisons. 

In  the  more  common  edema  of  chronic  nephritis  we  have  to 
consider,  among  other  factors,  the  blood  pressure.  That  this  is 
not  an  essential  or  even  important  cause,  however,  is  shown  by 
the  fact  that  edema  is  usually  much  less  marked  in  interstitial 
nephritis  with  high  blood  pressure  than  it  is  in  parenchymatous 
nephritis  with  a  much  lower  pressure.  Toxic  substances  are,  of 
course,  also  present  in  the  blood,  and  may  alter  capillary  per- 
meability ;  these  toxic  substances  may  account  for  the  localized 
edemas  and  erythemas  sometimes  observed  in  nephritis.  But 
probably  most  important  is  the  action  of  the  crystalloids  which  the 
kidney  does  not  excrete,  and  which  seem  to  be  stored  up  in  the 
tissues,  where  they  cause  transudation  of  water  under  the  influ- 
ence of  their  osmotic  pressure.  For  example,  Rzentkowski 2 
found  that  the  average  lowering  of  the  freezing-point  by  the 
edematous  fluid  in  nephritis  was  0.583°,  in  cardiac  dropsy  it 
was  0.548°,  and  in  tuberculous  pleuritis  0.526°.  This  indicates 
that  the  osmotic  concentration  of  the  fluid  is  highest  in  renal 

1  Amer.  Jour,  of  Physiol.,  1902  (7),  380. 
2Berl.  klin.  Woch.,  1904  (41),  227. 


GENERAL  CAUSES  OF  EDEMA  293 

dropsy,  and  supports  the  belief  that  here  and  in  cardiac  dropsy 
osmotic  pressure  plays  a  more  important  part  than  it  does  in 
inflammatory  exudation.  Of  the  crystalloids  that  cause  accu- 
mulation of  fluid  in  the  tissues,  sodium  chloride  seems  to  be  the 
most  important. 

Retention  of  Chlorides  in  Edema,1 — From  the  investigations  made 
by  numerous  clinicians,  especially  the  French,  there  seems  to  be  no 
question  but  that — (1)  in  nephritis  with  edema  a  retention  of  sodium 
chloride  frequently  occurs  ;  (2)  that  elimination  of  the  chlorides  is  often 
increased  during  periods  of  improvement  of  the  edema ;  (3)  that  a 
reduction  of  the  amount  of  chlorides  in  the  diet  often  causes  a  great 
improvement  in  the  edema,  while  administration  of  chlorides  may  make 
the  edema  much  worse.  There  are,  however,  observations  that  also 
indicate  that  chloride  retention  does  not  account  for  all  cases  of  renal 
dropsy,  for  many  instances  have  been  observed  in  which  the  above-men- 
tioned conditions  were  not  fulfilled.  Nevertheless,  it  cannot  be  denied 
that  chloride  retention  is  often  an  important  causative  factor  in  the 
edema  of  parenchymatous  nephritis.  If  the  retained  chlorides  obeyed 
the  ordinary  laws  of  diffusion,  we  should  expect  them  to  become  distrib- 
uted alike  in  the  blood  and  tissues,  so  that  they  would  merely  cause  an 
equal  increase  in  the  fluids  of  the  blood  and  of  the  tissues;  that  is  to 
say,  there  would  be  an  hydremic  plethora  due  to  retention  of  water  in 
the  body  by  the  accumulating  chlorides.  But,  according  to  a  number  of 
observers,  there  is  a  specific  retention  in  the  tissues,  which  Strauss  calls 
"  historetention,"  and  which  explains  the  local  edema.  The  way  in 
which  the  historetention  is  produced  is,  however,  not  understood,  and 
not  all  observers  accept  this  hypothesis  (Scheel 2).  In  many  conditions 
other  than  nephritis,  there  is  also  a  chloride  retention  (e.  g.,  pneumonia, 
cardiac  incompetence,  sepsis,  typhoid),  and  the  edemas  observed  in 
these  diseases  may  possibly  depend  upon  chloride  retention,  as  many 
French  authors  suggest.  Rumpf,  indeed,  often  found  more  chlorides  in 
edematous  fluids  of  non-nephritic  origin  than  in  nephritic  edema. 

Inflammatory  Edema. — Although  here  the  alterations  in 
the  capillary  walls  play  an  essential  role,  as'  shown  by  the  pro- 
teid-rich  nature  of  the  exudates,  yet  most  of  the  other  factors 
are  added.  Increased  blood  pressure  is  prominent ;  lymph  out- 
flow is  impeded  by  plugging  of  the  lymphatic  channels  by 
clots  and  leucocytes,  and  by  pressure  on  the  outside ;  there  is, 
undoubtedly,  an  excessive  formation  of  metabolic  products  in 
the  tissues,  to  cause  exosmosis.  To  this  class  of  edemas  belong 

1  Literature,   resum6  by  Widal  and  Javal,  Jour.  Physiol.  et  Pathol.,  1903 
(5),  1107  and  1123;  also  articles    by  Castaigne  and  Rathery,  Semaine  Med., 
1903  (23),  309  ;  Widal  and  Javal,  Presse  Med.,  1903  (11),  701;  Ambard  and 
Beaujard,  Semaine  Med.,  1905  (25),  133;  Koziczkowsky,  Zeit.  klin.  Med.,  1904 
(51),  287  ;  Bing,  Berl.  klin.  Woch.,  1905  (42),  1278  ;  Strauss,  Zeit.  klin.  Med., 
1902  (47),  337;  Ferrannini,  Cent.  f.  inn.  Med.,  1905  (26),  1;  Miller,  Jour. 
Amer.  Med.  Asso.,  1905  (45),  1915;  Rumpf,  Munch,  med.  Woch.,  1905  (52), 
393.     Review  in  Albu  and  Neuberg's  "  Mineralstoffwechsel,"  Berlin,  1906,  pp. 
171-178. 

2  Hospitalstidende,  1904,  p.  1017. 


294  EDEMA 

also  the  urticarias  which  follow  the  ingestion  of  various  toxic 
substances,  many  of  which  can  be  shown  experimentally  to  be 
lymphagogues.  A  good  example  is  the  urticaria  which  often 
follows  the  injection  of  antitoxic  or  other  foreign  serums,  par- 
ticularly their  repeated  injection ;  in  experimental  animals  such 
a  serum  may  cause  death  very  quickly  by  acute  pulmonary 
edema.  All  these  poisons  probably  produce  urticarial  edema 
by  injury  to  the  capillary  walls  in  the  subcutaneous  tissues  — 
probably  the  other  factors  are  not  important  in  this  condition. 
In  the  action  of  vesicants,  however,  it  may  well  be  questioned 
if  changes  in  the  capillary  walls  and  active  hyperemia  are  not 
supplemented  by  local  metabolic  alterations  and  osmotic  influ- 
ences. 

Neuropathic  Edema. — Until  we  understand  better  than 
we  now  do  the  manner  in  which  nervous  impulses  modify  metab- 
olism, it  will  be  difficult  to  estimate  properly  the  importance 
of  nervous  impulses  in  the  production  of  edema.  That  nervous 
control  is  a  possible  factor  is  well  shown  by  many  experi- 
ments ;  for  example,  simple  ligation  of  the  femoral  vein  in 
animals  does  not  cause  edema,  but  if  the  sciatic  nerve  is  cut 
the  vasoconstrictors  are  paralyzed,  and  edema  may  follow 
(Ranvier).  In  this  case  the  nervous  influence  is  only  indirect, 
through  its  vasomotor  effects.  Similarly,  stimulation  of  vaso- 
dilator fibers  may  cause  edema.  It  is  furthermore  possible  that 
nervous  stimulation  may  lead  to  excessive  metabolic  activity, 
with  an  accumulation  of  crystalloidal  products,  sufficient  to 
cause  edema  when  supplemented  by  active  congestion  and  some 
resulting  pressure  upon  the  lymph-vessels.  There  are  certainly 
many  instances  in  which  edema  seems  to  depend  upon  nervous 
disturbance ;  for  example,  edema  in  the  area  of  distribution  of 
a  neuralgic  nerve  ;  sudden  joint  effusions  in  tabetic  arthropathy  ; 
and  especially  the  typical  "  angioneurotic "  edema.  The  only 
explanation  that  seems  open  is  the  one  given  above,  namely,  a 
combination  of  local  hyperemia  and  increased  metabolic  activity. 

Hereditary  Edema. — In  a  number  of  families  there  has  been 
observed  a  peculiar  inherited  tendency  to  the  occurrence  of  acute 
attacks  of  local  edema,  which  not  infrequently  have  proved  fatal 
when  involving  the  glottis.1  There  can  be  little  question  that 
these  instances  of  hereditary  edema  depend  upon  a  nervous 
affection  of  some  kind,  it  being  practically  an  angioneurotic 
edema;  but  how  the  edema  is  produced,  and  what  the  nature 
of  the  nervous  alteration  may  be,  are  as  mysterious  as  are  most 
other  so-called  "  nervous  inheritances." 

1  Literature,  see  Fairbanks,  Amer.  Jour.  Med.  Sci.,  1904  (127),  877. 


COMPOSITION  OF  EDEMATOUS  FLUIDS 


295 


COMPOSITION  OF  EDEMATOUS  FLUIDS 

As  is  well  known,  the  composition  of  edematous  fluids 
varies  greatly  according  to  the  cause  of  the  edema  and  the 
place  where  it  occurs.  In  general,  non-inflammatory  edemas 
(transudates)  contain  much  less  proteid  than  do  the  inflam- 
matory exudates,  as  is  shown  by  the  following  table  of  analyses 

TABLE  I. 


Sp.  gr. 

Parts  per  100  of  fluid. 

Total 
proteid. 

Fibrin. 

Serum- 
globulin. 

Serum- 
albumin 

Acute  pleurisy  .... 

«          « 

«              a 

1.023 
1.020 
1.020 

5.123 
3.4371 
5.2018 

0.016 
0.0171 
0.1088 

3.002 
1.2406 
1.76 

2.114 
1.1895 
3.330 

Hydrothorax     j 
Aver,  of  3  cases  J 

1.014 

1.7748 

0.0086 

0.6137 

1,1557 

by  Halliburton  *  and  by  Bernheim's 2  determinations  of  proteids 
in  ascitic  fluids. 


TABLE  II. 


Ascitic  fluid  in 

Max. 

Min. 

Mean. 

Cirrhosis  of  the  liver 

34  5 

56 

9  69  21  06 

Bright's  disease  . 

1611 

10*10 

156     1036 

Tuberculous  and  idiopathic  peritonitis  . 
Carcinomatous  peritonitis    

55.8 
5420 

18.72 
2700 

30.7-37.95 
35  1  58  96 

Parts  of  proteid  to  1000  c.c.  fluid. 


The  specific  gravity  varies  nearly  in  direct  proportion  to  the 
amount  of  proteids,  that  of  transudates  usually  being  below  1.015, 
and  exudates  above  1.018,  although  there  are  many  exceptions. 
Indeed,  it  is  often  very  difficult  to  decide  whether  a  given  fluid 

1  Adami,  Allbutt's  System,  1896  (1),  97. 

2  Quoted  by  Hammarsten,  "Physiological  Chemistry"  (Amer.  ed.),  1904, 
p.  223. 


296 


EDEMA 


is  an  exudate  or  a  transudate.1  According  to  Rzentkowski,2  the 
transudates  at  the  moment  they  pass  out  of  the  vessels  are 
simply  solutions  of  crystalloids  in  water  and  quite  free  from 
proteid ;  the  small  amount  of  proteid  found  in  transudates  he 
ascribes  to  proteid  pre-existing  in  the  tissue-spaces.  This  idea 
is  hardly  acceptable  in  view  of  the  known  permeability  of  the 
vessel-walls  for  proteids  in  normal  conditions ;  more  probably 
in  cardiac  and  renal  dropsies  the  quantity  of  proteid  escaping 
from  the  vessels  is  not  greatly  different  from  normal,  but  the 
excessive  fluid  escaping  in  these  conditions  carries  with  it  no 
additional  proteids,  and  to  this  extent  transudates  in  statu  nas- 
cendi  are  proteid-free. 

Transudates,  even  when  produced  by  the  same  cause,  vary  in 
composition  in  different  parts  of  the  body,  presumably  because 
of  variations  in  the  permeability  of  the  vessels  in  different 
vascular  areas ;  just  as  pleural,  pericardial,  peritoneal,  and 
meningeal  fluids  normally  differ  from  one  another.  Thus  C.  S. 
Schmidt 3  found  the  composition  of  the  transudates  in  different 
parts  of  the  body  of  a  patient  who  died  of  nephritis  to  have  the 
following  composition  : 

TABLE  III. 


Pleural. 

Peritoneal. 

Subarachuoid. 

Subcutaneous. 

Water    

96395 

97891 

98354 

98870 

Solids  

3605 

21.09 

16.46 

11.30 

Organic  matter     
Inorganic  matter  

28.50 
7.55 

11.32 
9.77 

7.98 
8.48 

3.60 
7.70 

As  in  this  case,  the  general  rule  is  that  while  the  proportion 
of  salts  remains  nearly  constant,  the  proportion  of  proteid  in 
edematous  fluids  in  different  localities  varies  in  decreasing  order 
as  follows:  (1)  pleura;  (2)  peritoneum;  (3)  cerebrospinal ; 
(4)  subcutaneous.  In  the  last-named  location  the  specific 
gravity  of  edematous  fluids  may  be  as  low  as  1.005,  and  the 

1  Kivalta  (Kif.  Med.,  1903;  Biochem.  Centr.,  1904  (2),  529)  has  suggested 
the  following  test  to  distinguish  exudates  and  transudates :  Into  a  beaker  con- 
taining 200  c.c.  of  water  with  4  drops  of  glacial  acetic  acid,  let  fall  a  few  drops 
of  the  fluid  to  be  tested.     If  an  exudate,  a  bluish-white  line  is  left  transiently 
behind  the  sinking  drops,  due  to  precipitation  of  the  euglobulin  and  pseudo- 
globulin.     Memmi  (Clin.  Med.  Ital.,  1905,  No.  3)  suggests  the  larger  content 
of  lipase  as  a  means  of  distinction  of  exudates.     Tedeschi  (Gaz.  degli.  Osped., 
1905  (26),  88)  states  that  egg-albumen  fed  in  large  amounts  appears  in  trans- 
udates and  not  in  exudates,  and  can  be  detected  by  the  biological  precipitin 
test. 

2  Virchow's  Arch.,  1905  (179),  405. 

3  Hoppe-Seyler's  Physiol.  Chemie,  p.  607. 


COMPOSITION  OF  EDEMATOUS  FLUIDS  297 

proteids  even  less  than  0.1  per  cent.  (Hoffmann * ).  An  increase 
in  solids  occurs  after  the  effusion  has  existed  for  some  time, 
presumably  because  of  absorption  of  water  and  salts,  leaving  a 
slowly  increasing  proportion  of  proteids.  Furthermore,  the 
composition  of  the  patient's  blood  has  considerable  influence  on 
the  composition  of  the  effusion  ;  this  is  particularly  true  in  the 
case  of  ascites  from  portal  obstruction,  the  contents  of  the  blood 
coming  from  the  intestine  during  digestion  modifying  the 
composition  of  the  ascitic  fluid.  Thus  Miiller,2  in  a  case  of 
portal  vein  thrombosis,  found  in  the  ascitic  fluid  of  a  patient  on 
an  ordinary  mixed  diet,  0.179  per  cent,  nitrogen  ;  on  a  proteid- 
rich  diet,  0.2494  per  cent.  N ;  on  a  proteid-poor  diet,  0.1764 
per  cent.  N.  In  cachectic  conditions  the  proportion  of  proteids 
is  less  than  in  stronger  individuals,  and,  as  in  the  blood  plasma, 
the  albumin  decreases  more  rapidly  than  the  globulin  as  the 
cachexia  advances  (Umber3). 

Physical  Chemistry  of  Bdematous  Fluids. — The 
differences  between  transudates  and  exudates  depends  almost 
solely  on  their  proteid  contents,  for  the  non-proteid  elements 
are  almost  identical  with  normal  lymph  and  blood-serum,  which 
naturally  must  be  so  since  any  original  or  temporary  deviation 
in  osmotic  pressure  must  be  rapidly  equalized  by  diffusion. 
Thus  Bodon4  finds  the  concentration  of  the  electrolytes  nearly 
constant  in  spite  of  considerable  differences  in  composition  of 
various  edema  fluids,  indicating  that  the  serosa  permits  passage 
of  inorganic  salts  always  in  the  same  concentration,  while  hold- 
ing back  the  organic  substances.  Rzentkowski5  found  some 
slight  differences  in  molecular  concentration  as  indicated  by  the 
freezing-point ;  in  tuberculous  pleurisy  the  average  lowering 
was  0.523°,  that  of  the  serum  being  — 0.56°  ;  in  cardiac  dropsy 
the  subcutaneous  fluid  gave  — 0.548°,  and  in  renal  dropsy 
—0.583°;  tuberculous  peritonitis,  —0.523°;  cirrhosis  —0.536°; 
carcinomatous  edema — 0.547°.  Of  these  figures,  the  most  sig- 
nificant is  the  comparatively  high  molecular  concentration  of  the 
fluid  in  nephritis,  supporting  the  contention  that  the  cause  of  renal 
edema  is  retention  of  crystalloids.6  Tieken 7  has  found  the  fol- 
lowing results  in  transudates,  exudates,  and  other  body  fluids : 

1  Deut.  Arch.  klin.  Med.,  1889  (44),  313. 

2  Deut.  Arch.  klin.  Med.,  1903  (76),  563. 
8  Zeit.  klin.  Med.,  1903  (48),  364. 

4  Pfluger's  Arch.,  1904  (104),  519;  also  see  Galeotti,  Lo  Sperimentale,  1901 
(55),  425. 

5  Loc.  tit,  and  also  Berl.  klin.  Woch.,  1904  (41),  227. 

6  Purulent  exudates  may  show  a  high  molecular  concentration  (  -  0.84°  in  one 
case),  due  to  decomposition  of  the  proteids  into  crystalloids  (Kzentkowski). 

7  Amer.  Medicine,  1905  (10),  822. 


298 


EDEMA 


TABLE  IV. 


Nature  of  Fluid. 

Sp.  gr. 

Freezing- 
point  of 
effusion, 
—  °C. 

Freezing- 
point  of 
blood, 
—  °C. 

Disease. 

Pleuritic  effusion 

1,016 

-0.55 

-0.56 

Pneumonia,  lobar. 

a 

1,018 

-0.55 

-0.55 

u                   u 

u 

1,018 

-0.54 

-0.56 

Tuberculosis. 

a 

1,020 

-0.55 

-0.56 

u 

a 

1,016 

-0.55 

-0.56 

u 

" 

1,018 

-0.64 

-  0.56 

Valvular  heart  disease. 

(1 

Pericardial                .    . 

1,030 
1,018 

-0.60 
-0.55 

-0.58 
-0.56 

Empyema;  cyanosis. 
Pericarditis. 

"                         .    . 

1,016 

-0.56 

-0.56 

u 

Ascitic  fluid  .           .    . 

1,012 
1,024 

-  0.56 
-0.60 

-0.56 
-  0.56 

Hydropericardium. 
Cirrhosis  of  liver. 

u             a 

1,020 

-0.57 

-0.56 

«              u      u 

«              a 

1,018 

-0.58 

-0.56 

Tuberculous  peritonitis. 

U                   U 

1,013 

-0.62 

-0.56 

Organic  heart  disease. 

u                 (£ 

1,035 

-0.65 

-0.58 

General  peritonitis. 

Hydrocele  fluid    .    .    . 

1,016 

-0.56 

-0.56 

Tuberculosis. 

Cerebrospinal  fluid  .    . 

1,018 

-  0.62 

-  0.58 

Uremic  coma. 

u 

1,016 

-0.64 

-0.68 

<t          « 

u 

1,020 

-0.64 

-0.64 

«             « 

u 
(I 

1,014 
1,017 

-0.56 
-0.56 

-  0.56 
-0.56 

Tuberculous  meningitis. 
Epidemic  meningitis. 

« 

-0.56 

-0.56 

u                       « 

The  very  high  figures  for  effusions  in  nephritis  and  cardiac 
incompetence  indicate  the  concentration  of  crystalloids  in  these 
fluids,  and  support  the  belief  that  in  the  formation  of  both, 
osmotic  pressure  is  an  important  factor.1 

Edematous  fluids  are  usually  alkaline  except  when  bacterial 
changes  lead  to  acid  formation.  Bodon 2  found,  however,  that 
while  they  contain  alkali  that  can  be  neutralized  by  titration 
against  acids,  yet  they  resemble  the  blood  in  being  neutral  as 
far  as  the  presence  of  free  OH  ions  is  concerned. 

Proteid  Contents. — As  indicated  in  the  tables  given 
previously,  these  vary  greatly  in  quantity  in  various  fluids 3 ; 
the  quantitative  relations  of  the  different  varieties  of  proteids 
have  been  less  studied.  Serum-albumins  and  globulins  constitute 
by  far  the  largest  part  of  the  proteids,  fibrinogen  being  scanty 
except  in  some  inflammatory  exudates,  so  that  coagulation  very 

1  Meyer  and  His  (Deut.  Arch.  klin.  Med.,  1905  (85),  149)  claim  that  the 
lowering  of  the  freezing-point  is  less  than  that  of  the  blood  in  exudates  while 
forming,  the  same  as  the  blood  while  stationary,  and  greater  during  absorption, 
which  they  consider  indicates  a  "  vital  process"  on  the  part  of  the  cells. 

2  Loc.  cit. 

3  See  also  v.  Jaksch,  Zeit.  klin.  Med.,  1893  (23),  225 ;  Kzentkowski  (he.  cit.}. 


COMPOSITION  OF  EDEMATOUS  FLUIDS  299 

seldom  occurs  spontaneously ;  pneumococcus  exudates  seem 
particularly  rich  in  fibrinogen,  which  coagulates  rapidly  and 
firmly.  Joachim  l  found  in  pleural  transudates  and  exudates 
that  the  proportion  of  albumin,  euglobulin,  and  pseudoglobulin 
is  always  proportionally  lower  in  hydrothorax  than  in  pleurisy. 
Of  different  forms  of  ascites,  the  largest  proportion  of  globulin 
and  the  smallest  of  albumin  occur  in  cirrhosis ;  while  with 
carcinoma  the  proportions  are  reversed.  In  general  the  albumin 
is  more  abundant  than  the  globulin,  but,  as  Umber 2  has  found, 
the  proportion  of  albumin  sinks  more  rapidly  in  cachexia  than 
does  the  globulin,  corresponding  to  the  similar  changes  in  the 
blood  proteids.  The  amount  of  proteid  lost  in  exudates  is 
strikingly  shown  by  one  of  Umber's  cases  of  cancerous  ascites ; 
during  one  year  the  fluid  removed  by  paracentesis  contained  not 
less  than  three  kilos  of  pure  proteid,  the  patient  weighing  but 
55.5  kilos. 

Several  authors  have  found  in  inflammatory  ascitic  exudates 
a  proteid  having  physical  and  chemical  properties  much 
resembling  mucin ;  it  has  been  especially  studied  by  Umber,3 
who  finds  it  quite  similar  to  the  synovial  mucin  isolated  in 
arthritis  by  Salkowski,  and  calls  it  serosamucin. 

Proteoses,  leucin,  and  tyrosin  may  be  present  in  small  quan- 
tities in  exudates,  being  produced  by  autolysis  (Umber) ; 
and  also  mucoid  substances  (Hammarsten).  Nucleoproteids 
may  be  present  from  leucocytic  disintegration  in  exudates,  as 
well  as  the  products  of  their  further  splitting,  such  as  purin 
bases  and  phosphates.  Galdi  and  Appiani4  found  uric  acid 
constantly  in  amounts  between  0.0055  g.  and  0.0714  g.,  in  all 
exudates,  of  which  seven  were  tuberculous  and  two  neoplastic. 
In  three  transudates  amounts  from  0.006  to  0.011  were  found. 
Allantoin,  which  Pohl  states  is  a  characteristic  product  of 
nucleoproteid  autolysis,  has  been  found  in  exudates  (Moscatelli 5). 

All  the  other  innumerable  components  of  plasma  may  be 
found  in  edematous  fluids  ;  thus  sugar  (Pickardt 6 )  and  urea 
(Carriere 7 )  are  usually  present,  as  well  as  other  extractives. 
Lecithin  is  always  present,  partly  bound  to  globulin  and  partly 


1  ranger's  Arch.,  1903  (93),  558. 

3  Loc.  eit. 

3  Zeit.  klin.  Med.,  1903  (48),  364;  also  Hoist,  Upsalalakar.  Forhand, 
1904,  p.  304. 

*  Kiforma  Med.,  1904,  p.  1373 ;  also  Carriere,  Compt.  Kend.Soc.  BioL,  1899 
(51),  467. 

5  Zeit.  physiol.  Chem.,  1889  (13),  202. 

6  Berl.  klin.  Woch.,  1897  (34),  844. 

7  Loc.  cit. 


300  EDEMA 

free  (Christen1).  Cholesterin  is  present  particularly  in  fluids 
that  have  been  standing  for  a  long  time  in  the  body,  appearing 
often  as  visible  crystals  shining  in  the  fluid ;  it  probably  origi- 
nates from  degenerating  cells.  Glycogen  is  not  present  (Car- 
riere 2 ).  The  various  immune  bodies,  cytotoxins,  hemolysins, 
bacteriolysins,  agglutinins,  etc.,  seem  to  pass  freely  into  both 
transudates  and  exudates,  and  their  presence  is  not  characteristic 
of  either.3 

Toxicity. — Contrary  to  earlier  ideas,  transudates  are  not 
toxic,  even  in  nephritis  (Bay lac,4  Boy-Teissier,5  Lafforcade 6 ), 
and  therefore  the  toxic  manifestations  frequently  observed  after 
reduction  of  edema  in  nephritis,  and  ascribed  to  absorption  of 
poisons  in  the  transudates,  are  probably  due  to  some  other  cause. 
In  inflammatory  exudates,  of  course,  the  causative  agents  as 
well  as  the  products  of  cell  destruction  render  the  fluids  poisonous. 

Enzymes. — All  the  enzymes  of  the  plasma  may  appear 
in  edematous  fluids,  being  in  all  cases  probably  more  abundant 
in  exudates  than  in  transudates.  According  to  Carriere,7 
oxidases  are  inconstant,  even  in  exudates.  Lipase  is  said  to  be 
much  more  abundant  in  exudates  than  in  transudates.8  (Con- 
cerning proteolytic  enzymes  see  "Autolysis  of  Exudates," 
Chap,  iii.) 

Precipitin  Reactions,  etc. — Edematous  fluids  have  been 
often  used  as  a  source  of  material  in  immunizing  animals  against 
human  proteids.  The  precipitins  thus  formed  are  specific  for 
human  serum  or  for  the  proteids  of  the  effusion,  but  cannot  be 
used  to  differentiate  a  transudate  from  an  exudate,  or  a  hydro- 
thorax  fluid  from  an  ascites  fluid  (Quadrone9).  Immune  bodies, 
complement, agglutinins, and  antitoxins  are  present  in  effusions10; 
e.  g.j  the  common  use  of  blister  fluid  for  the  Widal  test.  Fur- 
thermore, according  to  Hamburger,11  edema  fluid  is  distinctly 
more  bactericidal  than  normal  lymph. 


1  Cent.  f.  inn,  Med.,  1905  (26),  329. 

2  Compt.  Kend.  Soc.  Biol.,  1899  (51),  467. 


3  Granstrom,  Inaug.  Dissert.,  St.  Petersburg,  1905. 

4  Compt.  Kend.  Soc.  Biol.,  1901  (53),  519. 

5  Ibid.,  1904  (56),  1119. 

6  Gaz.  heb.  Med.  et  Chir.,  Jan.  28,  1900. 

7  Compt.  Kend.  Soc.  Biol.,  1899  (51),  561. 

8  Zeri,  II  Policlinico,  1903  (10),  No.  11 ;    Memmi,  Clin.  Med.  ItaL,  1905, 
No.  3. 

9  Cent.  f.  Bakt.  (ref.),  1905  (36),  270. 

10  Granstrom,  loc.  cit. 

11  Virchow's  Arch.,  1899  (156),  329. 


COMPOSITION  OF  EDEMATOUS  FLUIDS  301 


VARIETIES  OF  EDEMATOUS  FLUIDS 

On  the  preceding  pages  have  been  mentioned  the  chief  dif- 
ferences in  the  characters  of  the  effusions  in  the  usual  sites/ 
with  their  variations  in  proteid  contents,  which  variation  agrees 
with  Starling's  statement  that  the  permeability  of  the  capillary 
wall  for  proteids  differs  normally  in  different  localities.  Some 
of  the  other  effusion  fluids  not  mentioned  previously  have 
particular  properties  of  some  interest. 

Hydrocele  and  Spermatocele  Fluids. — These  have 
been  studied  particularly  by  Hammarsten,2  who  found  the 
average  results  of  analyses  of  seventeen  hydrocele  fluids  and 
four  spermatocele  fluids  as  follows  : 

TABLE  V. 

Hydrocele          Spermatocele 

Water    .        938.85                 986.83 

Solids 61.15                  13.17 

Fibrin 0.59 

Globulin 13.25                    0.59 

Seralbumin 35.94                     1.82 

Ether-extractive  bodies  ......  4.02  ) 

Soluble  salts 8.60  \               10.76 

Insoluble  salts 0.66  J 

Marchetti 8  found  in  ten  specimens  of  hydrocele  fluid  rather  higher 
results  for  the  solids  than  did  Hamrnarsten.  He  found  57. 8  to  104. 2 
p.  m.  of  solids,  containing  organic  substances  48. 8  to  95.02,  and  inorganic 
substances  8.10  to  9.56  ;  proteids,  33.5  to  90. 19  ;  ratio  of  globulin  to 
albumin  as  2,56  to  9.11.  Among  the  proteids  is  found  1  to  4  p.  m. 
that  is  not  precipitated  by  heat.  Corresponding  with  the  analytic 
results,  the  specific  gravity  of  hydrocele  fluid  is  higher,  1.016  to  1.026  as 
against  1.006  to  1.010  for  spermatocele  fluid.  Cholesterin  is  often 
abundant  in  hydrocele  fluids,  appearing  to  the  naked  eye  as  glistening 
scales.  Patein 4  found  sugar  in  most  specimens  of  hydrocele. 

Mening-eal  Effusions.5 — Normal  meningeal  fluid  differs 
from  all  other  serous  fluids  in  being  clear  and  watery,  in  its 
low  specific  gravity  (1 .004  to  1 .007),  in  containing  but  a  trace  of 
proteid  which  is  chiefly  globulin  (with  a  trace  of  proteose  (?)),  and 
a  reducing  substance  that  is  not  sugar.6  Halliburton  gives  the 
following  analyses  of  pathological  accumulations  of  such  fluids  : 

1  Literature  and  re'sume'  on  pleuritic  exudates,  see  Ott,  Chem.  Pathol.  der 
Tuberc.,  1903,  p.  392. 

2  Physiological  Chemistry,  Amer.  ed.,  1904,  p.  223. 

3  Lo  Sperimentale,  1902  (56),  297. 

4  Jour,  pharm.  et  chim.,  1906  (23),  239;    also  Compt.  Kend.  Soc.  Biol., 
1906  (60),  303. 

5  Ke*sume"  by  Blumenthal,  Ergeb.  der  Physiol.,  1902  (1),  285. 

6  Halliburton's  "Chemical  Side  of  Nervous  Activity,"  1901,  p.  18;  see  also 
Halliburton's  "  Chemistry  of  Muscle  and  Nerve,"  1904. 


302  EDEMA 

TABLE  VI.  (Spina  bifida.) 


Water     

Casel 
•  .    .    989  75 

Case  2 
989.877 

Cases 
991.658 

Solids     
Proteids 

....      10.25 

0842 

10.123 

1.602 

8^342 
0.199 

Extractives  "I 

9626 

j  oiesi 

3^028 

Salts             / 

\  7.890 

5.115 

The  percentage  of  solids  in  spina  bifida  is  thus  a  little  higher 
than  in  normal  raeningeal  fluid.  In  hydrocephalus  the  per- 
centage of  solids  is  rather  greater,  as  seen  in  Table  VII. 

TABLE  VII.  (Hydrocephalus.) 

Case  1              Case  2  Case  3 

Water 986.78          984.59  980.77 

Solids 13.22            15.41  19.23 

Proteids  and  extractives  ....        3.74              6.49  11.35 

Salts 9.48              8.92  7.88 

Normal  cerebrospinal  fluid  seems  to  be  hypertonic  to  the 
serum  of  the  same  animal/  and  is  much  less  alkaline  than  the 
blood  (Cavazzani 2).  According  to  Fuchs  and  Rosenthal,3  the 
average  freezing-point  of  the  cerebrospinal  fluid  is  lowered  about 
the  same  in  all  diseases  (A  ~  —0.52°  to  — 0.54°)  except  in 
tuberculous  meningitis,  where  it  is  much  less  (average  — 0.43°). 
The  amount  of  potassium  is  usually  higher  than  in  other  body 
fluids,  according  to  Geoghegan  the  ash  containing  20  to  30  per 
cent,  of  potassium  salts  and  but  15  per  cent,  of  sodium  salts. 
The  amount  of  proteid  generally  varies  directly  with  the  number 
of  cellular  elements  present  in  the  fluid.4  In  diseases  associated 
with  destruction  of  brain  tissue,  such  as  general  paralysis  and 
epilepsv,  cholin  may  be  found  in  the  spinal  fluid.  (See 
"  Cholin,"  Chap,  iv.) 

Wound  secretions  obtained  from  large  aseptic  wounds,  mostly 
amputation  stumps,  have  been  studied  by  Lieblein.5  The  reaction  is 
generally  alkaline,  globulin  and  albumin  abundant,  but  fibrinogen 
scanty,  total  nitrogen  being  less  than  that  of  the  blood  and  decreasing 
from  day  to  day  ;  the  proportion  of  albumin  increases  and  globulin 
decreases  as  heal  ing  progresses.  Occasionally  albumoses  were  found,  but 
only  on  the  first  day  in  aseptic  wounds  ;  if  found  later,  they  generally 
were  antecedent  to  suppuration  (concerning  suppuration  see  ' '  Inflamma- 
tion," Chap.  X.). 

1  Kavaut,  Presse  me"d.,  1900  (8),  128 ;  Zanier,  Cent.  f.  Physiol.,  1896  (10), 
353. 

2  Cent.  f.  Physiol.,  1902  (15),  216. 

3  Wien.  med.  Presse,  1904  (45),  2081  and  2135. 

4  Ke"non  and  Tixier,  Compt.  Kend.  Soc.  Biol.,  1906  (60),  639. 

5  Beit.  klin.  Chir.,  1902  (35),  43. 


CHYLOUS  EFFUSIONS.  303 

Blister  fluid  is  generally  rich  in  solids  and  proteids  (40-65  p.  m.). 
In  a  burn  blister  Morner 1  found  50.31  p.  m.  proteids,  among  which  were 
11.59  p.  m.  globulin  and  but  0.11  p.  m.  fibrin  ;  also  a  substance  reduc- 
ing copper  oxide,  but  no  pyrocatechin. 

Chylotis  Effusions.2 — Fat  may  be  present  in  effusions  in 
sufficient  quantity  to  cause  a  milky  appearance,  either  from 
escape  of  chyle  from  a  ruptured  or  obstructed  thoracic  duct,  or 
through  fatty  degeneration  of  the  cells  in  the  effusion  or  the 
lining  of  the  walls  of  the  cavity.  The  former  are  designated 
as  chylous,  the  others  as  chyliform  or  adipose  fluids,  but  it  is 
not  always  easy  to  distinguish  between  them.  The  composition 
of  the  fluids  in  true  chylous  exudates  will  vary  according  to 
the  food  taken  and  the  amount  of  fat  the  food  contains,  and 
will  resemble  the  composition  of  chyle,  except  to  the  extent 
that  it  is  modified  by  the  absorption  going  on  in  the  cavity. 

Analyses  of  human  chyle  are  scanty.  The  most  recent  are  those  of 
Panzer  and  of  Carlier.  Panzer  3  found  90.29-94. 53  per  cent,  water  ; 
5.47-9.71  per  cent,  solids;  0.80-1. 04  per  cent,  inorganic  salts;  2.16 
per  cent,  coagulable  proteid  ;  6. 59  per  cent,  ether-soluble  material  ; 
also  diastatic  enzyme,  soaps,  and  occasionally  traces  of  cholesterin, 
lecithin,  and  sugar.  Carlier,*  in  a  specimen  from  a  child,  obtained 
very  similar  results,  except  that  the  salts  were  much  less  abundant. 

Edwards 5  found  but  60  definitely  established  cases  of  chylous 
or  chyliform  ascites  in  the  literature  up  to  1895  ;  and  of  31 
indisputable  cases  studied  at  autopsy,  in  21  there  was  established 
the  existence  of  a  rupture  in  the  thoracic  duct  or  lacteals.  Bos- 
ton6 in  1905  was  able  to  collect  126  cases,  including  both 
chylous  and  chyliform  ascites,  and  notes  an  associated  eosino- 
philia  in  a  case  studied  by  him.  Chylous  ascites  fluid  often, 
but  not  always,  contains  sugar,7  which  is  diagnostic  if  present 
in  more  than  traces,  and  if  diabetes  is  excluded,  but  it  may 
disappear  after  having  once  been  present ;  the  amount  of  fat  is 
small,  usually  about  1  per  cent.,  and  the  fluid  is  rich  in  solids. 
If  due  to  a  ruptured  thoracic  duct,  it  may  be  possible  to  detect 

1  Hammarsten,  Amer.  ed.,  1904,  p.  224. 

2  General   features    reviewed   by  Edwards,    Reference  Hdbk.   Med.   Sci., 
1901  (3),  78. 

3  Zeit.  physiol.  Chem.,  1900  (30),  113. 
*  British  Med.  Jour.,  1902  (ii),  175. 

5  Medicine,    1895   (1),  257,  gives  literature;  also  see  "Chem.  u.  morph. 
Eigenschaften  fetthaltige  Exsudaten,"  St.  Mutermilch,  Warschau,  1903  ;  Comey 
and  McKibben,  Boston  Med.  and  Surg.  Jour.,  1903  (148),  109. 

6  Jour.  Amer.  Med.  Assoc.,  1905  (44),  513. 

7  For  example,  v.  Tabora   (Dent.  med.  Woch.,  1904  (30),  1595)  found  as 
high  as  0.864  per  cent,  of  sugar  in  a  typical  case. 


304  EDEMA 

special  fats  taken  in  the  food,  e.  g.,  butter- fats  (Straus1).  The 
reaction  is  usually  alkaline  or  neutral,  and  some  specimens 
coagulate  spontaneously.  Specific  gravity  varies  from  1.007 
to  1.040,  the  average  being  about  1.017.  Perhaps  the  most 
important  characteristic  is  the  variation  produced  by  changes  in 
diet.2  Zdarek3  found  in  a  chyle-cyst  2.7  percent,  of  fats, 
7.2  per  cent,  of  proteids,  and  0.05  per  cent,  of  sugar ;  feed- 
ing of  fats  increased  their  amount  in  the  cyst  and  starvation 
decreased  it. 

Ascites  adiposus  is  characterized  by  the  absence  of  sugar 
and  by  a  higher  percentage  of  fat,  the  maximum  observed 
being  6.4  per  cent.  In  a  case  examined  by  Edwards  the 
composition  was  as  follows:  Specific  gravity,  1.012;  proteid, 
2.7  per  cent. ;  fat,  6  per  cent. ;  diastatic  ferment  and  sugar 
absent.  This  form  occurs  principally  as  a  result  of  fatty  meta- 
morphosis of  cells,  particularly  in  carcinomatous  and  tuberculous 
exudates ;  Edwards  was  able  to  show  experimentally  that  a 
transudate  may  change  from  serous  to  cellular,  and  later  come 
to  contain  fat. 

Pseudochylous  effusions  are  also  observed,  not  only  in  the 
abdominal  and  thoracic  cavities,  but  even  in  the  fluid  of  the 
edematous  legs  and  scrotum  ;  these  resemble  chylous  fluids  in 
being  turbid  or  milky,  but  they  contain  no  fat.4  The  turbidity 
is  apparently  due  chiefly  to  lecithin,  which  is  largely  combined 
with  the  pseudoglobulin  of  the  fluid  (Joachim 5  ).  Possibly  in 
some  cases  the  turbidity  is  partly  or  largely  (Poljakoif 6)  due 
to  poorly  dissolved  proteids.  Strauss 7  has  noted  the  occurrence 
of  this  form  of  ascites  particularly  in  chronic  parenchymatous 
nephritis,  but  believes  the  turbidity  has  a  local  origin.  Ham- 
marsten  has  observed  a  similar  turbidity  due  to  mucoid  sub- 
stances, as  also  have  Gouraud  and  Corset.8 

1  Arch.  Physiol.  et  Pathol.,  1886  (Ser.  3,  vol.  8),  367. 

2  A  sample  of  the  composition  of  1  liter  of  chylous  ascitic  fluid  is  shown 
by  the   analysis   in   the   case   studied  by   Comey  and  McKibben  (loc.    cit.) : 
Specific  gravity,  1.010 ;   solids,  21  gm. ;  proteids,  9.75  gm. ;  urea,  1.28  gm. ; 
fat,  1.45  gm.  ;  inorganic  matter,  8  gm.  ;  peptone  (?)  and  sugar,  present;  fibrino- 
gen,  mucin,  nucleo-albumin,  and  uric  acid  absent. 

3Zeit.  f.  Heilk.,1906  (27),  1. 

4  Literature,  see  Bernert,  Arch.  exp.  Path.  u.  Pharm.,  1902  (49),  32. 

5  Munch,  med.  Woch.,  1903  (50),  1915 ;  also  Christen,  Cent.  f.  inn.  Med., 
1905  (26),  329. 

6  Fortschr.  d.  Med.,  1903  (21),  1081. 

7  Note  to  Poljakoffs article;  also  Biochem.  Centr.,  1903  (1),  437. 
8Compt.  Eend.  Soc.  Biol.,  1906  (60),  23. 


CHEMISTRY  OF  PNEUMOTHORAX  305 

CHEMISTRY   OF   PNEUMOTHORAX 

In  connection  with  the  subject  of  exudates  the  above  topic 
may  appropriately  be  considered.  The  com  position  of  the  gases 
found  in  the  pleural  cavity  in  pneumothorax  will  necessarily 
vary  greatly  according  to  the  cause.  If  the  pleural  cavity  is 
in  free  communication  with  the  exterior,  the  gas  will  be  simply 
slightly  modified  air ;  for  example,  Ewald l  found  the  following 
proportions  in  the  gases  in  such  a  pneumothorax:  CO2,  1.76 
per  cent.  ;  O,  18.93  per  cent.  ;  and  79.31  per  cent.  N.  Here 
the  proportion  of  CO2  is  even  a  little  less  than  in  ordinary  expired 
air,  which  contains  3.3-3.5  per  cent.  When  air  enters  a  closed 
pleural  cavity  and  no  effusion  follows,  it  is  slowly  absorbed. 
At  first  there  is  a  rapid  absorption  of  oxygen,  which  is  partly 
replaced  by  CO2,  with  a  resulting  relative  increase  in  nitrogen. 
Ordinarily  the  entrance  of  air  into  the  pleural  cavity  is  followed 
by  an  effusion,  either  serous  or  purulent,  which  may  modify  the 
composition  of  the  gas.  In  a  seropneumothorax  Ewald  found 
8.13  per  cent,  of  CO2,  1.26  per  cent,  of  O,  and  90.61  percent, 
of  N,  which  is  quite  similar  to  the  proportions  of  the  gases  in 
dry  pneumothorax.  Purulent  pneumothorax  generally  shows 
more  CO2  than  the  serous  form,  the  average  in  the  former  being 
15-20  per  cent.,  in  the  latter  7.5-11.5  per  cent.  The  average 
of  the  analyses  in  six  cases  of  pyopneumothorax  is  given  by 
Ewald  as  18.13  per  cent.  CO2,  2.6  per  cent.  O,  and  79.81  percent. 
N.  In  open  pyopneumothorax  the  gas  approaches  more  closely 
the  composition  of  air,  but  usually  shows  a  slight  excess  of  CO2 ; 
it  is  thus  possible  by  a  determination  of  the  carbon  dioxide  to 
determine  quite  accurately  whether  a  given  pneumothorax  is 
in  communication  with  the  outside  air.  The  transformation 
of  a  purulent  into  a  putrid  pneumothorax  is  accompanied  by  an 
increase  of  CO2,  even  as  high  as  40  per  cent,  having  been 
found.  The  products  of  decomposition  by  the  putrefactive 
saprophytes  also  are  present,  one  analysis  having  shown  4.3 
per  cent,  of  hydrogen,  6.25  per  cent,  of  methane,  and  traces 
of  hydrogen  sulphide. 

Infection  of  a  pleural  effusion  by  gas-producing  organisms 
may  also  convert  it  into  a  pneumothorax,  although  this  is  not  a 
common  occurrence.  The  gases  then  present  are  the  same  as 
the  organisms  produce  in  similar  culture-media,  modified  some- 
what by  absorption.  The  anaerobic  gas-producing  organisms 
have  been  found  as  the  cause  of  such  gaseous  accumulations ;  it 

1  Complete  literature  and  re"sum£  given  by  Clemens,  in  Ott's  "  Chem.  Path, 
der  Tubemilose,"  Berlin,  1903,  p.  406. 

20 


306  EDEMA 

is  questionable  if  the  ordinary  pathogenic  organisms  can  cause 
a  pneumothorax,  since  they  are  for  the  most  part  not  capable  of 
producing  gas.  The  colon  bacillus  produces  gas  in  sugar-con- 
taining media,  but  the  amount  of  sugar  in  the  pathological 
exudates  is  too  small  to  yield  any  considerable  amount  of  gas ; 
an  exception  is  the  pleural  effusion  in  diabetes,  and  pneumo- 
thorax from  infection  of  the  pleural  effusion  in  a  diabetic  by 
I>.  coli  has  been  reported.  Complete  quantitative  analyses  of 
the  gas  in  this  form  of  pneumothorax  seem  not  to  have  been 
made,  but  May  found  about  20  per  cent,  of  CO2.  The  com- 
bustibility of  the  gas  has  frequently  been  noted,  and  is  prob- 
ably due  to  hydrogen  and  methane. 


CHAPTER    XIII 

RETROGRESSIVE  CHANGES  (NECROSIS,  GAN- 
GRENE, RIGOR  MORTIS,  PARENCHYMATOUS 
DEGENERATION) 

NECROSIS 

WE  recognize  that  a  cell  is  alive  through  its  reproducing, 
functionating,  and  its  taking  on  and  utilizing  nutritive  sub- 
stances ;  yet  at  the  same  time  we  appreciate  that  a  cell  may  do 
none  of  these  things  and  still  be  alive.  For  example,  a  bac- 
terial spore  is  quite  inert  physically,  and  exhibits  no  chemical 
activity,  yet  it  is  by  no  means  dead,  since  it  still  possesses  the 
latent  power  to  again  assume  an  active  existence  under  suitable 
conditions.  In  pathological  conditions  we  are  accustomed  to 
recognize  the  fact  that  a  cell  is  dead  by  certain  alterations  in  its 
structural  appearance,  particularly  disintegrative  changes  in  the 
nucleus ;  but  this  is  exactly  equivalent  to  recognizing  that  an 
animal  is  dead  by  the  appearance  of  postmortem  decomposition, 
for  most  of  the  characteristic  histological  changes  of  necrosis  are 
merely  postmortem  changes  in  the  cell.  A  cell  may  be  dead 
and  show  absolutely  none  of  these  microscopic  disintegrative 
changes,  either  because  it  has  not  been  dead  long  enough  for 
them  to  have  taken  place,  or  because  the  changes  have  been 
prevented  by  some  means,  just  as  we  can  prevent  the  appearance 
of  postmortem  decomposition  by  embalming.  For  example, 
if  we  examine  microscopically  the  mucous  membrane  of  the 
stomach  of  a  person  who  has  died  immediately  after  taking  a 
large  quantity  of  carbolic  acid,  although  to  the  naked  eye  this 
mucous  membrane  is  hard,  white,  and  definitely  necrotic,  yet 
we  find  the  histological  picture  presented  by  the  cells  almost 
absolutely  unchanged  from  the  normal.  The  cells  are  dead,  but 
they  have  been  so  "  fixed  "  that  postmortem  changes  could  not 
affect  their  structure.  All  cells  examined  by  ordinary  histo- 
logical methods  are,  of  course,  dead — killed  by  the  fixing  agents 
outside  of  the  body,  in  the  same  way  that  the  carbolic  acid  fixes 
them  within  the  body.  It  is  evident,  therefore,  that  it  may  be 
very  difficult  to  determine  always  whether  a  cell  is  dead  or  not. 
Part  of  the  difficulty,  perhaps,  lies  in  our  failure  to  appreciate 

307 


308  EETROGEESSIVE  CHANGES 

that  not  all  parts  of  a  cell  die  at  the  same  time  ;  i.  e.,  the  causes 
of  different  chemical  processes  of  the  cell  reside  in  its  different 
intracellular  enzymes,  and  these  are  not  necessarily  destroyed 
alike  by  the  same  agents. 

We  recognize  that  after  an  animal  is  dead  as  a  whole  the 
various  cells  of  its  body  do  not  die  for  some  time,  as  shown  by 
the  following  examples :  (1)  We  can  cause  the  heart  to  beat 
for  a  considerable  period  after  its  removal  from  the  body ;  (2) 
if  we  perfuse  a  mixture  of  glycocoll  and  benzoic  acid  through 
the  kidney  of  a  recently  killed  animal,  synthesis  of  these  sub- 
stances into  hippuric  acid  will  occur ;  and  (3)  the  epithelium  of 
the  skin  can  be  removed  from  the  body  of  an  animal  long  after 
death  and  transplanted  successfully  on  another  animal.  So,  too, 
in  ordinary  cell  death  (necrobiosis)  not  all  the  enzymes  are 
destroyed  together.  When  all  are  destroyed  at  once,  as  by 
strong  chemicals  or  by  heat,  the  customary  disintegrative  changes 
do  not  take  place.  If,  however,  not  all  the  enzymes  are  thrown 
out  of  function,  then  the  others  may  be  able  to  act,  producing 
the  disintegrative  changes  by  which  histologists  ordinarily 
recognize  cell  death.  These  disintegrative  changes  are,  for  the 
most  part,  apparently  brought  about  by  the  intracellular  pro- 
teases, that  is,  through  autolysis.  This  may  be  shown  as 
follows  : l  If  we  take  two  pieces  of  fresh  normal  tissue  from  an 
animal,  and  in  one  kill  the  enzymes  by  heating  to  100°  C., 
then  implant  both  aseptically  into  the  abdominal  cavity  of  an 
animal  of  the  same  species,  it  will  be  found  that  the  changes 
that  follow  in  the  two  will  be  very  unlike.  In  the  unheated 
tissue  nuclear  changes  soon  occur,  so  that  they  lose  their  capac- 
ity for  taking  up  basic  stains,  the  cytoplasm  becomes  granular 
and  fragmented,  the  tissue  becomes  friable  so  that  it  is  difficult 
to  secure  good  sections,  and  the  changes  are  in  general  similar 
to  those  seen  in  areas  of  necrosis.  The  boiled  tissue,  on  the 
other  hand,  retains  its  capacity  for  nuclear  staining  for  months, 
except  at  the  periphery,  where  it  is  slowly  attacked  by  leucocytes 
and  the  enzymes  of  the  blood  plasma.  Therefore  it  would  seem 
that  the  characteristic  changes  of  necrosis  depend  chiefly  upon 
the  intracellular  enzymes,  rather  than  upon  the  infiltrating 
plasma  as  Weigert2  and  other  early  writers  imagined.  In 
areas  of  anemic  necrosis  (see  "  Infarcts  "  )  we  have  another  case, 
in  which  the  oxidizing  enzymes  are  thrown  out  of  function 
through  lack  of  oxygen,  while  the  other  enzymes  are,  presum- 
ably, at  first  unaffected.  From  studies  of  infarcts  it  would  seem 

1  Wells,  Jour.  Med.  Kesearch,  1906  (15),  149. 

2  Cent.  f.  Path.,  1891  (2),  785. 


NECROSIS  309 

that  the  intracellular  proteases  bring  about  the  subsequent 
nuclear  and  cytoplasmic  alterations,  but  that  the  eventual 
digestion  of  the  area  is  accomplished  by  the  invading  leucocytes 
working  slowly  inward  from  the  periphery.  Apparently  when 
the  supply  of  materials  from  outside  ceases,  and  when  the  oxi- 
dation processes  of  the  cells  no  longer  accomplish  necessary 
steps  of  synthetic  reactions  or  destroy  products  of  proteid  catab- 
olism,  the  proteases  continue  to  split  proteids  without  the  balan- 
cing by  the  above-mentioned  factors,  with  a  resulting  disintegra- 
tion of  the  cells. 

Karyolysis  and  karyorrhexis  are,  then,  the  result  of  an  auto- 
lytic  process,  which  is  perhaps  due  to  intracellular  proteases  that 
act  specifically  on  nucleoproteids,  and  which  may  be  designated  as 
nudeases.1  Nuclear  staining  by  the  usual  methods  depends 
upon  an  affinity  of  the  acid  nucleoproteids  (in  which  the 
nucleic  acid  is  not  completely  saturated  by  proteids)  for  basic 
dyes.  Presumably  in  karyolysis  the  first  step  consists  in  a 
splitting  of  the  nucleoproteid  of  the  chromatin  into  nucleic 
acid  and  proteid ;  this  can  be  accomplished,  according  to  Sachs, 
by  the  ordinary  trypsin,  and  presumably,  therefore,  by  the  tryp- 
sin-like  enzymes  of  the  cell.  Corresponding  with  this  change 
we  should  expect  the  free  nucleic  acid  to  give  an  intense  stain- 
ing with  basic  stains,  and  this  has  frequently  been  described  by 
those  who  have  studied  the  cytological  changes  in  anemic 
necrosis,2  and  called  pycnosis.  As  supporting  this  view  still 
further  may  be  quoted  Arnheim's3  observation  that  in  alkaline 
solutions  the  nucleus  soon  stains  diffusely  and  weakly,  and  not 
at  all  after  twelve  to  eighteen  hours  ;  this  is  to  be  explained  by 
the  fact  that  nucleic  acid  is  both  dissolved  and  neutralized  by 
alkaline  solutions.  After  the  nucleic  acid  has  been  freed  from 
the  proteid  by  the  autolytic  enzymes,  it  is  still  further  decom- 
posed by  the  "  nuclease  "  or  similar  intracellular  enzymes  that 
have  the  property  of  splitting  nucleic  acid  into  the  purin  bases 
that  compose  it — corresponding  with  this  change  the  hyper- 
chromatic  nucleus  loses  its  affinity  for  stains,  and  karyolysis  is 
complete. 

It  may  be  observed  that  autolysis  of  aseptically  preserved 
tissues  outside  the  body  is  much  more  rapid  than  is  the  autol- 
ysis of  infarcts  and  similar  aseptic  necrotic  areas  within  the 

1  Jones,  Araer.  Jour.  Physiol.,  1903  (10),  p.  xxiv ;  Zeit.  physiol.  Chem.,  1903 
(41),  101 ;  ibid.,  1906  (48),  110.     Sachs,  Zeit.  physiol.  Chem.,  1905  (46),  337. 

2  Schmaus  and  Albrecht,  Virchow's  Arch.,  1895  (138),  supp.,  p.  1 ;  Ergeb. 
allg.  Pathol.,  1896  (3),  486  (literature). 

3  Virchow's  Arch.,  1890  (120),  367. 


310  RETROGRESSIVE  CHANGES 

body.  This  may  be  due  to  either  or  both  of  two  factors  : l 
First,  autolysis  is  much  slower  in  alkaline  than  in  acid  media ; 
outside  the  body  autolyzing  tissues  develop  an  acid  reaction 
which  favors  their  autolysis ;  within  the  body  this  is  checked 
by  the  alkaline  plasma.  Second,  the  plasma  contains  autolysis- 
inhibitiug  substances,  which  also  may  interfere  with  self-diges- 
tion in  the  body.  In  corroboration  of  the  above  may  be 
recalled  the  fact  that  large  necrotic  areas  show  autolysis  first  in 
the  center,  where  the  alkaline,  antagonistic  body  fluids  pre- 
sumably cause  the  least  effect.  Furthermore,  it  has  been  found 
by  Wells2  that  the  histological  changes  of  autolysis  proceed 
much  faster  in  serum  that  has  been  heated  to  destroy  the  anti- 
bodies than  in  unheated  serum.  Leucocytes,  as  Opie  has  shown, 
contain  autolytic  enzymes  acting  best  in  an  alkaline  medium, 
hence  they  perform  their  digestive  function  readily  at  the 
periphery  of  necrotic  areas. 

When  a  cell  dies,  certain  physical  changes  occur  that  are 
probably  of  considerable  importance.  The  permeability  of 
the  cell  wall  is  almost  immediately  increased,  so  that  all  diffusible 
substances  readily  pass  through,  i.  e.y  its  semiperm cable  character 
is  lost.  This  we  see  particularly  in  plant  cells,  which  lose  their 
turgor  with  their  semipermeability,  and  therefore  the  plant 
wilts.  Galeotti3  has  studied  the  changes  in  cells  that  occur 
with  their  death,  and  finds  that  the  electrical  conductivity 
decreases  considerably  at  the  time  of  death,  while  the  molecular 
concentration  remains  quite  the  same.  This  indicates  that  the 
number  of  free  ions  is  diminished,  while  the  number  of  osmoti- 
cally  active  molecules  remains  constant ;  which  Galeotti  inter- 
prets as  meaning  that  living  protoplasm  is  characterized  by  a 
high  degree  of  ionization.  When  secondary  disintegrative 
changes  occur  in  the  protoplasm,  with  the  formation  of  many 
small  molecules  from  the  large  molecules  of  the  cell,  both 
osmotic  pressure  and  electrical  conductivity  increase  rapidly. 

CAUSES  OF  NECROSIS 

Anemia. — After  the  cutting  off  of  blood-supply,  cells  soon 
undergo  morphological  changes  that  we  recognize  as  indi- 
cating their  death,  and  after  a  time  they  also  become  incapable 
of  returning  to  their  normal  condition  when  the  blood-supply  is 
re-established,  probably  because  of  these  structural  changes. 

1  Literature  and  more  complete  discussion  under  "Autolysis." 

2  Jour.  Med.  Research,  1906  (15),  149. 

3  Zeit.  f.  Biol,  1903  (45),  65. 


CAUSES  OF  NECROSIS  311 

In  just  what  way  lack  of  nourishment  causes  death  has  not 
been  determined,  but,  as  has  been  before  suggested,  it  seems 
probable  that  it  is  because  catabolic  processes  are  no  longer 
balanced  by  anabolic  processes,  and  with  these  latter  oxidizing 
enzymes  seem  to  be  inseparably  associated,  so  far  as  our  present 
knowledge  shows  us.  Were  it  not  that  the  proteolytic  enzymes 
continue  in  action  after  nutrition  is  shut  off,  the  cells  might 
remain  in  a  completely  unaltered  condition  for  an  indefinite 
period,  and  capable  of  resuming  their  functions  when  nourish- 
ment is  again  supplied,  which  is  decidedly  contrary  to  the  facts. 
(The  general  features  of  anemic  necrosis  have  been  already  dis- 
cussed in  the  preceding  paragraphs,  and  also  under  the  subject 
of  infarction.) 

Thermic  Alterations. — These  have  been  studied  partic- 
ularly in  connection  with  the  cells  of  the  lower  organisms.1 
While  some  unicellular  organisms  can  survive  a  temperature  of 
69°,  most  of  them  are  killed  at  from  40°-45°.  For  the  great 
majority  of  metazoa  the  maximum  temperature  lies  below  45°, 
and  in  the  case  of  marine  species  below  40°.2  The  heating  is 
accompanied  by  the  appearance  of  granules  in  the  cytoplasm, 
which  become  larger  until  the  condition  of  "heat  rigor"  sets 
in.  Kiihne,  in  1864,  showed  that  in  muscle  cells,  at  least,  there  is 
contained  a  proteid  which  becomes  turbid  through  partial  coag- 
ulation at  40°,  and  Halliburton3  has  found  that  in  nearly  all 
tissues  are  globulins  coagulating  at  from  45°-50°  ;  it  is  prob- 
able, therefore,  that  the  granules  formed  in  heated  cells  are 
produced  through  coagulation  of  these  proteids.  The  impor- 
tance of  this  coagulation  in  determining  death  is  not  yet  fully 
established,  but  it  would  seem  to  be  very  great.  Halliburton  has 
observed  that  in  both  muscles  and  nerves  to  which  heat  is  applied, 
contractions  occur  at  various  temperatures,  corresponding  exactly 
with  the  temperatures  at  which  the  several  varieties  of  the  pro- 
teids of  the  cell  coagulate.  Furthermore,  Mott 4  has  found  that  the 
temperature  that  is  immediately  fatal  to  mammals  (47°)  is 
exactly  the  same  as  the  coagulating  temperature  of  the  lowest 
coagulating  proteid  of  nerve-cells.  This  fact  is  undoubtedly  of 

1  Literature,  see  Davenport,  "  Experimental  Morphology,"  New  York,  1897  J 
Schmaus  and  Albrecht,  Ergebnisse  der  Pathol.,  1896  (3,  Abt.  1 ),  470. 

2  The  adaptation  of  animal  cells  to  high  temperatures  is  an  interesting  topic, 
especially  in  view  of  such  results  as  those  of  Dallinger,  who,  by  raising  the 
temperature  gradually  during  several  years,  caused  flagellata  with  a  normal 
maximum  of  about  21°-23°  to  become  capable  of  living  at  70°  (see  Daven- 
port). 

1 "  Biochemistry  of  Muscle  and  Nerve, "  Phila.,  1904. 
*  Quoted  by  Halliburton. 


312  RETROGRESSIVE  CHANGES 

great  practical  importance  in  causing  death  from  fever,  for 
although  47°  C.  (117°  F.)  is  probably  never  reached  in  man, 
yet  application  of  much  lower  temperatures,  even  42°  (108°  F.), 
for  a  few  hours  will  cause  coagulation  of  these  proteids  (all  pro- 
teids  coagulate  at  less  than  their  ordinary  coagulation  point  if 
the  heating  is  continued  for  a  long  time).  It  would  seem  from 
the  above  observation  that  heat  causes  cell  death  through  coag- 
ulation of  the  proteids.  Whether  the  cell  death  is  in  any  way 
dependent  upon  destruction  of  the  enzymes  by  heat  has  not 
been  ascertained  ;  but  as  most  enzymes  are  not  destroyed  much 
below  60°— 70°,  it  seems  improbable  that  they  are  greatly 
injured  at  the  temperatures  at  which  cells  are  killed.  It  is 
possible,  however,  that  under  the  conditions  in  which  enzymes 
exist  in  the  cell  they  may  be  more  susceptible  to  heat  than 
under  normal  conditions.  Just  how  coagulation  of  cell  globu- 
lins can  determine  the  death  of  a  cell  is  difficult  to  understand, 
unless  the  physical  conditions  of  the  cell  are  greatly  altered 
thereby.  Ordinarily  we  have  in  the  cell  an  equilibrium  between 
colloids  in  solution  and  colloids  in  the  solid  or  gel  state ;  if  the 
colloids  are  rendered  insoluble  by  heat,  so  that  this  equilibrium 
is  destroyed,  serious  alterations  in  the  mechanism  of  all  metab- 
olism must  result  (Mathews). 

Different  tissues  show  unequal  susceptibility  to  heat.  "Wer- 
hovsky l  found  the  blood  most  affected  by  raising  the  tempera- 
ture of  living  animals,  next  the  liver,  kidneys,  and  myocardium 
in  order,  the  other  tissues  being  little  or  not  at  all  structurally 
injured. 

Cold  is  well  withstood  by  unicellular  forms,  and  relatively 
poorly  by  more  complex  organisms,  particularly  by  those  with  a 
highly  developed  circulatory  system ;  this  is  because  individual 
cells  are  not  greatly  affected  by  freezing,  whereas  the  circulatory 
channels  are  readily  blocked  by  this  cause.  Bacterial  cells  are 
not  killed  by  exposure  for  long  periods  to  the  temperature  of  liquid 
air2  ( — 190°).  Reduction  of  the  temperature  of  plant  cells  to 
—13°  may  result  in  a  granular  transformation  of  the  cytoplasm, 
often  with  rather  serious  structural  alterations.  Cytoplasm  seems 
to  be  more  affected  than  the  nucleus,  for  mitosis  may  occur  slowly 
in  plant  cells  at  — 8°,  and  Uschinsky 3  noted  that  in  animal  tis- 
sues the  nuclei  were  less  affected  by  cold  than  the  cytoplasm. 
Blood  seems  little  affected  by  freezing  temperature,  for  du  Cornu 
found  that  dog's  blood  kept  on  ice  for  five  to  ten  days  could  be 

1  Ziegler's  Beitr.,  1895  (18),  72. 
2MacFadyen,  Lancet,  1900  (i),  849. 
8  Ziegler's  Beitr.,  1893  (12),  115. 


CAUSES  OF  NECROSIS  313 

employed  for  transfusion  without  causing  hemoglobinuria. 
Grawitz  saw  motion  persist  in  human  ciliated  epithelium  kept 
for  seven  to  nine  days  on  ice.  Ciliated  epithelium  from  the  mouth 
of  the  frog  may  survive  cooling  to  — 90°,  and  frog  eggs  are  not 
killed  by  — 60°.  In  many  cells,  however,  the  physical  changes 
produced  by  freezing,  and  also  by  the  subsequent  thawing,  are 
sufficient  to  render  them  incapable  of  further  existence.  Cells 
devoid  of  or  poor  in  water  cannot  be  killed  by  freezing,  hence 
it  is  probable  that  the  currents  set  up  about  the  crystals  of  ice 
in  thawing,  as  well  as  the  rapid  contraction  and  expansion  under 
the  influence  of  the  cold  and  the  ice  formation,  are  the  cause  of 
the  effects  of  freezing,  which,  therefore,  are  not  dependent  upon 
chemical,  but  upon  physical,  alterations. 

In  the  case  of  warm-blooded  animals,  the  gangrene  following 
freezing  depends  not  so  much  upon  the  freezing  of  the  cells 
themselves  as  upon  the  formation  of  hyaline  thrombi  in  the 
injured  vessels  (v.  Recklinghausen,  Hodara1).  Kriege2  found 
that  if  the  freezing  is  transitory,  the  thrombi  may  again 
disappear ;  if  over  two  hours  in  duration,  they  are  persistent. 
Rischpler, 3  however,  considers  that  cell  death  is  due  primarily 
to  the  effect  of  the  cold  upon  the  cells. 

I/ight. — Light  may  affect  tissues  seriously,  apart  from  the 
effects  of  accompanying  heat.  In  the  treatment  of  lupus  by 
the  Finsen  method  with  concentrated  light  rays,  the  action  is 
largely  a  stimulating  one,  but  associated  with  or  subsequent  to 
a  certain  degree  of  cell  injury.  Ogneff 4  found  that  moderate 
action  of  electric  light,  rich  in  violet  and  ultraviolet  rays, 
causes  mitotic  cell  division  ;  if  the  action  is  stronger,  the  cells 
undergo  amitotic  division  and  then  become  necrotic.  The 
destruction  of  bacteria  by  light  is  a  well-known  phenomenon, 
but  it  has  been  suggested  that  their  destruction  depends  rather 
upon  the  action  of  substances  produced  in  the  culture-medium 
under  the  influence  of  light  than  upon  the  effect  of  the  light 
upon  the  bacterial  cells  themselves.  In  view  of  the  fact  that 
enzymes  in  solution  are  quite  readily  weakened  or  destroyed  by 
the  action  of  light,  it  is  possible  that  intracellular  enzymes  may 
be  similarly  destroyed  by  light,  with  resulting  cell  death.  How- 
ever, in  the  case  of  bacteria,  at  least,  the  effects  of  light  seem 
to  depend  upon  oxidation  processes,  for  in  the  absence  of  oxy- 
gen, bacteria  are  not  seriously  injured  by  light,  and  D'Arcy  and 
Hardy 5  found  that  "  active  oxygen "  is  formed  by  the  same 

1  Munch,  med.  Woch.,  1896  (43),  341.      2  Virchow's  Arch.,  1889  (116),  64. 
3  Ziegler's  Beitr.,  1900  (28),  541.  4  Pfliiger's  Arch.,  1896  (63),  209. 

5  Jour,  of  Physiol.,  1895  (17),  390. 


314  RETROGRESSIVE  CHANGES 

portion  of  the  spectrum  that  is  most  active  in  destroying  bac- 
teria, Whether  oxidative  processes  are  the  cause  of  death  in 
animal  cells  is  not  known,  but  we  are  familiar  with  many 
chemical  reactions  of  various  sorts  that  are  initiated  or  checked 
by  the  action  of  light.1  Thus,  bilirubin  is  oxidized  into  bili- 
verdin,  when  acted  upon  by  sunlight,  even  when  not  in  contact 
with  air ;  many  vegetable  oils  are  oxidized  by  sunlight,  and  it 
is  probable  that  the  oxidizing  action  of  light  upon  organic 
compounds  is  of  wide-spread  occurrence.  It  is,  therefore, 
quite  possible  that  such  oxidative  changes  may  be  the  cause  of 
necrosis  produced  by  the  action  of  light  rays. 

x-rays  produce  necrosis  which  is  peculiar  in  that  an  in- 
terval of  several  days,  or  even  weeks,  may  elapse  after  the  ex- 
posure before  the  necrosis  manifests  itself.  Ellis,2  who  has 
studied  the  literature,  considers  that  the  amount  of  necrosis  is 
out  of  proportion  to  the  changes  in  the  vessels,  which  some 
have  believed  to  be  the  cause  of  x-ray  gangrene,  and  therefore 
that  the  cells  must  be  directly  injured.3  That  x-rays  have  a 
marked  effect  on  metabolism  has  been  abundantly  established. 
According  to  Musser  and  Edsall,4  the  effect  of  x-rays  upon 
metabolism  is  unequalled  by  any  other  therapeutic  agent,  and 
is  manifested  by  excessive  elimination  of  the  products  of  pro- 
teid  destruction,  which  arise  particularly  from  the  lymphatic 
structures.5  These  changes  have  been  studied,  therefore,  par- 
ticularly in  connection  with  the  treatment  of  leukemia  (q.  v.). 
The  renal  epithelium  seems  also  to  suffer  injury  in  some  cases.6 
Radium,  which  shares  with  x-rays  the  power  of  causing  tissue 
necrosis,  does  not  have  a  similar  effect  upon  the  blood,  nor  do 
the  ultra-violet  rays  (Linser  and  Helber 7). 

The  long-continued  action  of  x-rays  upon  the  skin  has,  in 
many  cases,  led  to  the  formation  of  cancer,  apparently  because 
the  proliferation  stimulated  by  the  rays  progresses  until  it  ex- 
ceeds normal  bounds.8 

As  the  metabolic  changes  produced  by  x-rays  indicate  an 

1  See  Davenport,  "  Experimental  Morphology,"  1897,  p.  162. 

2  Amer.  Jour.  Med.  Sci.,  1903  (125),  85. 

3  Allen  (Jour.  Med.  Kesearch,  1903  (9),  462)  states  that  protozoa  and 
vinegar  eels  are  killed  by  long  exposure  to  x-rays,  whereas  plants  are  decidedly 
stimulated  in  their  growth. 

4 Univ.  Penn.  Med.  Bull.,  1905  (18),  174. 

5  A  peculiar  selective  action  for  the  generative  cells  is  also  shown  by  oxrays, 
which  cause  marked  atrophy  of  the  ovaries  and  testicles.     (See  Albers-Schon- 
berg,  Munch,  med.  Woch.,  1903  (50),  1859;  Frieben,  ibid.,  1903  (50),  2295; 
Specht,  Arch.  f.  Gyn.,  1906  (78),  458  ;  Thaler,  Deut.  Zeit.  Chir.,  1905  (79),  576. 

6  See  Schulz  and  Hoffman,  Deut.  Zeit.  f.  Chir.,  1905  (79),  350. 

7  Deut.  Arch.  klin.  Med.,  1905  (83)  479. 

8  See  review  by  Wyss,  Beitr.  z.  klin.  Chir.,  1906  (49),  185. 


CAUSES  OF  NECROSIS  315 

extremely  high  rate  of  autolysis,  one  may  ascribe  the  effects 
either  to  a  stimulating  effect  of  oj-rays  upon  autolytic  enzymes, 
or,  as  Neuberg l  does,  to  an  inhibitive  action  of  arrays  and 
radium  rays  upon  the  other  intracellular  enzymes  without  a 
corresponding  deleterious  effect  upon  the  autolytic  enzymes. 
This  hypothesis  agrees  with  the  facts  at  hand,  but  more  details 
concerning  the  effects  of  these  rays  upon  various  enzymes  are 
needed.  The  long  latent  period  before  the  appearance  of  ne- 
crosis after  exposure  to  x-rays  is  difficult  to  explain,  and  agrees 
rather  with  the  hypothesis  of  slow  proliferative  and  obstructive 
changes  in  the  blood-vessels. 

Electricity. — The  effects  of  the  electric  current  upon  cells 
are  described  by  Davenport  as  follows  :  A  weak  constant  cur- 
rent causes  a  centripetal  flowing  of  the  protoplasm  (in  Aetino- 
sphcerium)  ;  if  the  current  is  increased  or  long  continued,  the 
cytoplasm  of  the  pseudopodia  becomes  varicose,  and  droplets 
are  formed  which  soon  burst,  causing  a  collapse  of  the  proto- 
plasmic framework.  Finally,  the  protoplasm  on  the  anode  side 
begins  to  disintegrate,  and  the  loose  particles  move  toward  the 
positive  electrode  ;  eventually  the  cell  structure  may  be  entirely 
destroyed.  If  an  alternating  current  is  used,  both  anode  and 
cathode  side  of  the  cell  are  affected.  In  moving  organisms 
electric  currents  determine  direction  of  motion,  even  certain 
vertebrates  (tadpoles,  fish)  being  made  to  orient  themselves 
according  to  the  current.  The  nucleus  seems  to  be  more  sus- 
ceptible to  harm  by  electric  currents  than  the  cytoplasm 
(Pfeffer 2 ),  and  there  seems  to  be  no  oxidation-process  involved 
in  cell  destruction  by  electricity  (as  is  the  case  with  light  rays), 
for  the  effects  are  much  the  same  in  the  absence  of  oxygen 
(Klemm).  Schmaus  and  Albrecht  state  that  the  effect  of  elec- 
tricity upon  protoplasm  depends  upon  a  loosening  of  the  cohe- 
sion and  a  solution  of  the  constituents  of  the  cell  (vacuoliza- 
tion),  which  last  is,  perhaps,  due  to  direct  chemical  alterations. 
It  may  be  suggested  that  the  electric  current  causes  a  migration 
of  ions  toward  one  or  the  other  pole  of  the  cell,  in  this  way 
separating  the  movable  inorganic  ions  of  the  ion-proteid  com- 
pounds of  the  cell  from  the  immobile  colloidal  proteid  ions,  with 
consequent  serious  alterations  in  the  chemistry  of  the  cell. 
Zeit 3  found  that  continuous  currents  kill  bacteria  through  the 
production  of  antiseptic  substances  in  the  culture-medium,  but 
do  not  harm  them  directly. 

1  Zeit.  f.  Krebsforschung,  1904  (2),  171. 

2  Literature  given  by  Davenport,  "  Experimental  Morphology." 

3  Jour.  Amer.  Med/Assoc.,  1901  (37),  1432,  literature. 


316  RETROGRESSIVE  CHANGES 

Jellinek  l  has  studied  extensively  the  cause  of  death  after 
severe  electric  shocks,  and  finds  that  there  are  produced  intra- 
cerebral  hemorrhages  and  degeneration  of  the  nerve-cells,  which 
are  sufficient  to  explain  the  death  of  the  individual  without 
having  recourse  to  the  more  indefinite  idea  of  "  shock/7  Cun- 
ningham 2  considers  fibrillary  contraction  of  the  heart  as  the 
cause  of  death.3 

Chemicals  cause  cell  death  whenever  they  are  of  such  a 
nature  as  to  either  coagulate  the  cell  proteids  or  to  destroy  its 
enzymes.  The  action  of  such  substances  as  sulphuric  acid, 
strong  caustics,  etc.,  hardly  calls  for  explanation.  Phenol  (car- 
bolic acid)  may  cause  necrosis  and  gangrene  even  when  in  very 
dilute  solutions ;  this  appears  to  be  due  more  to  the  production 
of  hyaline  thrombi  of  agglutinated  red  corpuscles  in  the  capil- 
laries than  to  direct  action  upon  the  cells.  In  some  unpub- 
lished experiments  on  the  subject  of  "  carbolic  acid  gangrene," 
I  found  this  action  of  phenol  very  striking  when  dilute  solu- 
tions were  placed  on  the  web  of  a  frog's  foot,  under  the  micro- 
scope ;  as  soon  as  the  solution  penetrated  to  a  capillary,  stasis 
with  fusion  of  the  corpuscles  occurred  in  a  very  few  seconds. 
Similar  results  have  been  obtained  by  Rosenberger.4  Some 
poisons  seem  to  cause  necrosis  without  destroying  the  autolytic 
enzymes,  in  which  case  the  cells  are  rapidly  digested ;  at  least, 
such  a  hypothesis  seems  best  to  explain  the  changes  seen  in  the 
liver  in  chloroform  poisoning,  acute  yellow  atrophy,  eclampsia, 
etc.5  Not  all  poisons,  by  any  means,  cause  cell  death — tetanus 
toxin,  morphine,  and  other  alkaloids  cause  death  of  the  indi- 
vidual as  a  whole  without  usually  causing  primary  necrosis  of 
any  of  the  cells.  Cell  death  does  not  necessarily  depend  upon 
destruction  of  all  the  cellular  enzymes,  as  has  been  pointed  out 
previously.  Thus,  bacteria  may  be  killed  by  many  chemicals 
which  seem  not  to  affect  their  autolytic  enzymes  seriously. 

The  term,  "protoplasmic  poison,"  has  been  variously  used 
and  defined.  Kunkel  says  that  a  protoplasmic  poison  "  is  a 
poison  which,  without  producing  directly  evident  alterations, 
harms  or  kills  all  living  protoplasmic  structures."  HgCl2  is 
such  a  poison,  whereas  H2SO4,  bromine,  and  similar  substances 
that  destroy  all  life  through  their  strong  chemical  action  are  not 
included  in  this  category.  The  protoplasmic  poisons  presum- 

1  Virchow's  Arch.,  1902  (170),  56;  Lancet,  1903  (i),  357. 

2  New  York  Med.  Jour.,  1899  (70),  581. 

3  Full  discussion  by  Jelliffe  in  Peterson  and  Haines'  "  Legal  Medicine  and 
Toxicology,"  1903  (1),  245. 

4  Verb.  Phys.  Med.  Gesellsch.  z.  Wiirzburg,  1900,  vol.  34. 

5  Wells,  Jour.  Amer.  Med.  Assoc.,  1906  (46),  341. 


CAUSES  OF  NECROSIS  317 

ably  act  by  combining  with  one  or  more  of  the  constituents  of 
cell  protoplasm  ;  e.  g.,  HgCl2  probably  combines  with  the  pro- 
teids,  chloroform  with  the  cell  lipoids  (physically?).  Kunkel 
suggests  that  oxalic  acid  and  fluorides  are  poisons  because  they 
combine  the  cell  calcium,  and  barium  salts  may  be  poisonous 
because  they  precipitate  the  SO4  ions.  We  can  readily  imagine 
that  the  combining  of  even  one  of  the  essential  constituents  of 
the  cell  may  so  upset  the  normal  chemical  processes  that  the 
cell  can  no  longer  take  up  substances  to  repair  its  waste,  and 
hence  necrosis  ensues.1 

Physical  agents  may  cause  necrosis,  usually  in  ways  too 
obvious  to  require  explanation.  With  most  cells,  large  portions 
of  the  cytoplasm  can  be  destroyed  without  serious  results,  for  so 
long  as  the  nucleus  is  intact  the  cytoplasm  can  be  reconstructed. 
The  fact  that  necrosis  frequently  follows  relatively  slight  inju- 
ries of  the  nucleus  is  perhaps  best  explained  by  considering  that 
injury  to  the  nuclear  membrane  modifies  the  permeability  of  the 
nucleus  for  substances  in  solution,  which  might  readily  affect 
its  metabolic  activities  to  a  serious  degree.  It  is  possible,  also, 
that  solvents  of  lipoids,  such  as  chloroform,  etc.,  produce  much 
of  their  deleterious  effects  by  modifying  the  permeability  of  the 
cell,  since  the  semipermeability  of  cell  membranes  depends 
largely  upon  the  lipoids  they  contain.2 

Physical  injury  of  even  slight  degree  may  bring  on  severe 
alterations  in  cells,  however,  and  indeed  may  cause  severe 
chemical  alterations.  We  know  that  many  chemical  reactions 
can  be  brought  about  by  slight  mechanical  disturbances,  e.  g., 
the  explosion  of  fulminate,  nitrogen  iodide,  etc.,  and  it  is  quite 
possible  that  mechanical  disturbances  can,  likewise,  cause  chem- 
ical changes  in  the  protoplasm.  Many  lower  animals  devoid 
of  a  nervous  system  respond  to  mechanical  stimuli  by  chemical 
activity ;  e.  g.,  the  production  of  phosphorescence  by  marine 
organisms  when  agitated  by  an  oar,  etc.  Possibly,  the  secretion 
of  thrombokinase  by  the  leucocytes,  which  occurs  whenever  they 
come  in  contact  with  a  foreign  body,  is  an  example  of  a  similar 
reaction  to  a  mechanical  stimulus.  We  have  no  good  evidence, 
however,  that  mere  contact  with  a  chemically  inert  foreign 
body,  unaccompanied  by  cellular  injury,  can  cause  death  of 
tissue-cells.3 

1  It  is  hardly  profitable  here  to  go  further  into  the  theories  of  the  action  of 
poisons,  which  are  generally  extensively  considered  in  the  treatises  on  toxicol- 
ogy and  pharmacology  (also  by  Davenport,  loc.  dt.). 

2  See  Pascucci,  Hofmeister's  Beitrage,  1905  (6),  552. 

3Meltzer  (Zeit.  f.  Biol.,  1894  (30),  464)  has  shown  that  bacteria  may  be 
killed  by  violent  agitation,  which  causes  disintegration  of  the  cells. 


318  RETROGRESSIVE  CHANGES 

Extreme  changes  in  osmotic  pressure  may  lead  to  cell 
death,  either  by  causing  structural  alteration  in  the  cell  (e.  g., 
the  bursting  of  plant-cells  in  water),  or  concentration  of  the 
electrolytes  may  become  so  great  that  the  colloids  are  thrown 
out  of  solution,  as  in  the  ordinary  salting-out  processes  of  the 
laboratory.  It  is  doubtful,  however,  if  osmotic  changes  per  se 
ever  become  so  abnormal  within  the  animal  body  (except  in 
experimental  conditions)  as  of  themselves  to  cause  cell  necrosis. 

VARIETIES   OF   NECROSIS 

Coagulation  Necrosis.' — This  name  is  applied  to  ne- 
crotic  areas  that  are  firm,  dry,  usually  pale  yellowish  in  color, 
and  observed  principally  in  areas  of  total  anemia  or  tubercu- 
losis. The  question  has  been  long  disputed  as  to  whether  a 
true  coagulation  occurs  in  such  tissues  or  not.  Necrosis  pro- 
duced by  heat,  carbolic  acid,  corrosive  sublimate,  etc.,  is  natur- 
ally a  coagulation  necrosis,  the  cells  of  the  aifected  area  having 
undergone  true  coagulation ;  i.  e.,  the  conversion  of  their  solu- 
ble colloids  (sols)  into  the  insoluble  "pectous"  modification. 
Whether  the  same  change  occurs  in  areas  of  anemic  necrosis  is 
not  so  well  established.  If  the  part  contains  a  fair  amount  of 
plasma  the  liberation  of  the  tissue  coagulins  from  the  dead 
cells  will  cause  a  conversion  of  the  fibriuogen  into  fibrin — this 
can  usually  be  demonstrated  microscopically,  but  the  presence 
of  fibrin  is  not  constant,  and  its  quantity  is  usually  insufficient 
to  explain  satisfactorily  the  condition  of  coagulation  necrosis  in 
infarcts,  etc.,  as  Weigert  maintained.2  Schmaus  and  Albrecht 
believe  that  a  true  coagulation  of  the  cell  proteids  does  occur 
in  anemic  infarcts,  etc.,  for  they  found  that  the  cells  of  kidneys 
with  ligated  vessels  contain  at  first  granules  soluble  in  water 
and  salt  solution ;  after  forty -eight  hours  the  granules  cannot 
be  dissolved  in  these  solvents  or  in  weak  acetic  acid,  but  are 
soluble  in  2  per  cent.  KOH ;  after  five  to  six  days  the  granules 
are  insoluble  even  in  KOH.  Beyond  these  experiments,  we  seem 
to  have  no  proof  of  the  occurrence  of  intracelmlar  coagulation 
within  areas  of  coagulation  necrosis  due  to  anemia ;  exact  chemical 
studies  on  this  point  are  much  needed.  Since  tissue-cells  contain 

1  Literature  by  Jores,  Ergebnisse  der  PathoL,  1898  (5),  16. 

2  Weigert  believed  that  the  dead  area  becomes  permeated  by  plasma  contain- 
ing fibrinogen,  which  is  coagulated  in  and  between  the  cells.     He  put  much 
weight  on  an  increase  in  size  of  the  necrotic  area,  which  is  by  no  means  con- 
stant, as  he  intimated  ;  necrotic  areas  are  inelastic,  and  when  death  occurs,  they 
do  not  shrink  with  the  fall  of  blood  pressure  as  the  surrounding  tissues  do,  and 
hence  they  may  appear  to  project  from  the  surface  of  the  dead  organ  when 
they  did  not  do  so  during  life. 


LIQUEFACTION  NECROSIS,    CASSATION  319 

coagulins  for  fibrinogen,  it  is  possible  that  they  also  contain  coag- 
ulins  for  cell-proteids,  but  this  remains  to  be  established.  Bacteria 
produce  substances  coagulating  milk  and  fibrinogen,  and  Ruppel l 
found  that  the  tubercle  bacillus  produces  substances  precipitating 
proteids  ;  hence  coagulation  necrosis  in  bacterial  infections  may 
be  brought  about  in  this  way ;  and  Schmoll 2  has  shown  that 
the  necrosis  occurring  in  tubercles  is  associated  with  an  almost 
complete  coagulation  of  the  cell-proteids. 

Necrosis  associated  with  inflammatory  exudation  is,  of  course, 
accompanied  by  coagulation  of  the  fibrinogen  of  the  exudate 
(e.  g.j  diphtheria) ;  this  type  of  coagulation  necrosis  is  chemic- 
ally a  simple  fibrin-formation  and  readily  understood.  The 
peculiar  hyaline  degenerations  of  parenchymatous  cells  (e.  g., 
Zenker's  degeneration  of  muscles)  are  often  included  under  this 
class,  but  it  would  seem  more  probable  that  the  processes  con- 
sist rather  of  the  fusion  of  the  structural  elements  of  the  cell 
into  a  homogeneous  substance  than  a  true  coagulation.  No  exact 
data  are  at  hand  concerning  this  point,  however. 

I/iquefaction  necrosis  occurs  particularly  in  the  central 
nervous  system,  where  the  cell  substance  seems  not  to  undergo 
the  coagulative  changes  described  in  the  preceding  paragraphs. 
Whether  this  is  due  to  a  lack  of  tissue-coagulins  or  to  a  dif- 
ference in  cell  composition  cannot  be  said,  but  the  large  pro- 
portion of  lipoids  in  brain  tissue  is  probably  an  important  factor. 
Probably  "edema  ex  vacuo"  is  responsible  for  much  of  the 
accumulation  of  fluid,  due  to  the  anatomical  conditions  that 
prevent  a  shrinking  or  collapse  of  the  tissues  to  fill  in  the  gap, 
and  the  lack  of  connective- tissue  formation.  Aseptic  softening 
in  general  may  be  safely  ascribed  to  digestion  of  proteids  by 
cellular  enzymes,  either  from  the  dead  cells  or  from  the  leuco- 
cytes. Suppuration  is  merely  a  form  of  liquefactive  necrosis, 
in  which  such  digestion  is  particularly  rapid  because  of  the 
large  number  of  leucocytes  that  are  present.  Necrosis  of  the 
gastric  mucosa  or  of  the  pancreas  is  also  followed  by  rapid 
liquefaction,  through  the  action  of  the  digestive  enzymes  of 
these  tissues.  When  necrosis  is  accompanied  by  edema  (as  in 
superficial  burns),  the  fluid  enters  the  cells  in  large  amounts, 
presumably  because  of  increased  intracellular  osmotic  pressure, 
and  in  this  way  another  form  of  liquefaction  necrosis  may  be 
produced. 

Caseation. — This  term  is  applied  to  a  form  of  coagulation 
necrosis  in  which  the  dead  tissue  has  an  appearance  quite  similar 

1  Zeit.  physiol.  Chem.,  1898  (26),  218. 
2Deut.  Arch.  klin.  Med.,  1904  (81),  163. 


320  RETROGRESSIVE  CHANGES 

to  that  of  cheese.  If  we  bear  in  mind  the  fact  that  cheese  is  a 
mixture  of  coagulated  proteid  and  finely  divided  fat,  and  that 
in  caseation  we  have  a  coagulation  of  tissue  proteids  associated 
with  the  deposition  of  considerable  quantities  of  fat,  the  reason 
for  the  gross  resemblance  of  the  product  of  this  form  of  necrosis 
to  cheese  is  apparent.  Schmoll l  has  analyzed  caseous  material, 
and  found  it  almost  entirely  free  from  soluble  proteids  or  prote- 
oses.  The  proteid  material  is  almost  solely  coagulated  proteid, 
which  in  its  elementary  composition  is  related  to  the  simple 
proteids  or  to  fibrin,  and  not  at  all  to  the  nucleoproteids.  The 
extremely  small  amount  of  phosphorus  present  in  the  caseous 
material  indicates  that  the  products  of  disintegration  of  the  cell- 
nuclei  must  diffuse  out  early  in  the  process.  Caseation  is,  there- 
fore, characterized  by  a  coagulation  of  the  proteids  and  a  dis- 
solving out  of  the  nuclear  components.  Schmoll  does  not 
explain  the  cause  of  coagulation,  however.  It  may  be  that  it 
is  the  same  as  in  the  coagulation  of  anemic  infarcts  (since 
tuberculous  areas  are  decidedly  anemic),  or  possibly  the  tuber- 
cle bacillus  produces  substances  coagulating  proteids,  as  Ruppel 2 
states  is  the  property  of  "  tuberculosamin."  Indeed,  Auclair 3 
claims  that  the  fatty  substance  that  can  be  extracted  from 
tubercle  bacilli  by  chloroform  is  the  cause  of  the  caseation. 
Dead  tubercle  bacilli  do  not  produce  true  caseation,  however, 
according  to  Kelber 4 ;  hence  the  substance  causing  the  necrosis 
evidently  does  not  diffuse  readily  from  the  bodies  of  the  bacilli. 
The  abundance  of  fat  in  caseous  material  is  very  striking. 
Bossart5  found  from  13.7  per  cent,  to  19.4  per  cent,  of  the  dry 
substance  of  caseous  material  soluble  in  alcohol  and  ether.  In 
the  scrapings  from  tuberculous  bovine  glands  I  have  found  22.7 
-23.9  per  cent,  of  the  organic  material  soluble  in  alcohol  and 
ether.6  Of  this  soluble  material,  Bossart  found  25  to  33  per 
cent,  of  cholesterin,  and  Leber7  found  38.31  per  cent,  of  leci- 
thin, which  is  a  much  higher  proportion  than  Bossart  detected. 
Presumably  these  fatty  materials  are  derived  chiefly  from  the 
disintegrated  cells ;  this  is  probably  true  of  the  lecithin  and 
cholesterin,  but  the  fact  that  in  histological  preparations  most 
of  the  fat  is  found  about  the  periphery  of  the  caseous  area,8 

1  Deut.  Arch.  klin.  Med.,  1904  (81),  163. 

2  Loc.  cit. 

3  Arch.  meU  exper.,  1899,  p.  363. 

*  Quoted  by  Diirck  and  Oberndorfer,  Ergebnisse  der  Pathol.,  1899  (6),  288. 

5  Quoted  by  Schmoll,  loc.  cit. 

6  Wells,  Jour.  Med.  Research,  1906  (14),  491. 

7  Quoted  by  Schmoll. 

8Sata,  Ziegler's  Beitr.,  1900  (28),  461. 


FAT  NECKOSIS  321 

supports  the  belief  that  it  has  wandered  in  from  the  outside.1 
A  certain  proportion  of  the  fat  is  probably  derived  from  the 
bodies  of  the  tubercle  bacilli,  which  usually  contain  about  40 
per  cent,  of  fatty  matter ;  but  it  has  not  been  determined 
whether  the  fat  from  this  origin  forms  an  appreciable  part  of 
the  fatty  matter  of  caseous  material. 

Caseous  areas  persist  for  extremely  long  periods  of  time  with- 
out undergoing  absorption,  which  indicates  that  the  autolytic 
enzymes  are  destroyed  early  in  the  process,  presumably  by  the 
toxins  of  the  tubercle  bacillus ;  corresponding  to  this  Schmoll 
found  autolysis  very  slight  indeed  in  caseous  areas.  Because 
of  a  lack  of  chemotactic  substances  no  leucocytes  enter  to 
remove  the  dead  material.  That  the  failure  of  absorption  is 
not  due  to  a  modification  of  the  proteids  into  an  indigestible 
form  is  shown  by  the  rapid  softening  of  caseous  areas  when, 
through  mixed  infection,  chemotactic  substances  are  once  de- 
veloped and  leucocytes  enter. 

FAT  NECROSIS.2 

Through  usage  this  term  has  come  to  indicate  a  specific  form 
of  necrosis  of  fat  tissue,  which  is  characterized  by  a  focal,  cir- 
cumscribed arrangement,  and  by  the  splitting  of  the  fat  in  the 
necrotic  area  into  fatty  acids  and  glycerin,  the  latter  disappear- 
ing, the  former  combining  with  bases  to  form  soaps.3  In  all 
cases  fat  necrosis  is  produced  by  the  action  of  pancreatic  juice 
upon  fat  tissue,4  presumably  through  the  action  of  the  enzymes 
it  contains,  and  the  condition  can  be  produced  experimentally 
by  any  procedure  that  causes  escape  of  the  pancreatic  juice 
from  its  natural  channels. 

Langerhans5  made  the  first  studies  of  the  nature  of  the 
changes  in  fat  necrosis,  and  established  the  fact  that  the  fat  of 
the  cells  is  split  into  its  components,  and  that  the  fatty  acids 
combine  (at  least  in  part)  with  calcium.  Dettmer6  found  that, 

1  Fischler  and  Gross  (Ziegler's  Beitr.,   1905  (7th  suppl.),  344)  could  find 
no  fatty  acids  in  caseous  areas  by  histological  methods. 

2  General  literature  will  be  found  in  the  articles  cited  in  the  text ;  also  in 
Opie's  "  Diseases  of  the  Pancreas,"  1903  ;  and  in  Truhart's  "  Pankreas-Pathol- 
ogie,"  Wiesbaden,  1902. 

3  The  fatty  acids  form  masses  of  crystals  in  the  fat-cells,  and  they  can  also 
be  demonstrated  microchemically  by  Benda's  method  (Virchow's  Arch.,  1900 
(161),  194),  which  consists  of  staining  with  a  copper  acetate  mixture,  blue- 
green  copper  salts  of  the  fatty  acids  being  formed. 

4  Wulff  (Berl.  klin.  Woch.,  1902  (39),  734)  claims  to  have    observed  an 
exception  to  this  rule,  but  his  account  is  not  by  itself  convincing. 

5  Virchow's  Arch.,  1890  (122),  252. 

6  Dissertation,  Gottingen,  1895. 

21 


322  RETROGRESSIVE  CHANGES 

although  fresh  pancreatic  juice  caused  fat  necrosis,  a  commercial 
preparation  of  trypsin  did  not  do  so,  and,  therefore,  he  con- 
cluded that  probably  the  lipase  of  the  pancreatic  juice  was  the 
active  agent.  Flexner1  supported  this  contention  by  demon- 
strating the  presence  of  a  fat-splitting  enzyme  in  foci  of  fat 
necrosis,  which  was  corroborated  by  Opie.2  The  latter 3  was  also 
able  to  demonstrate  the  presence  of  lipase  in  the  urine  of  a 
patient  with  fat  necrosis.4 

In  a  study  of  the  pathogenesis  of  fat  necrosis,  particularly 
with  reference  to  the  question  whether  the  lipase  or  the  trypsin 
of  the  pancreatic  juice  was  responsible,  Wells5  found  that  typi- 
cal fat  necrosis  could  be  produced  by  injecting  extracts  of  fresh 
pancreas  into  animals,  either  of  the  same  species  as  that  from 
which  the  pancreas  was  obtained,  or  into  a  foreign  species. 
Commercial  "  pancreatins "  were  also  quite  effective,  whether 
in  weak  acetic  acid  or  weak  alkaline  solutions.  The  power  of 
these  materials  to  cause  fat  necrosis  was  reduced  by  heating  to 
or  above  60°  for  five  minutes,  and  completely  destroyed  at  71°, 
indicating  that  the  active  agent  is  an  enzyme.  But,  as  in  the 
same  material  trypsin  was  injured  by  temperatures  above  60°, 
and  destroyed  at  between  70°  and  72°,  and  lipase  was  weakened 
above  50°,  and  destroyed  above  70°,  it  was  impossible  to  deter- 
mine, by  heating  pancreatic  preparations,  whether  the  lipase  or 
the  trypsin  was  the  essential  factor.  By  permitting  pancreatic 
extracts  to  digest  themselves  it  was  found  that  the  power  to 
produce  fat  necrosis  decreased,  pari  passu,  with  the  decrease  in 
lipolytic  strength.  Preparations  strongly  tryptic,  but  very 
weak  in  lipase,  produced  no  fat  necrosis,  and,  on  the  other 
hand,  extracts  of  pig's  liver  or  of  cat's  serum,  both  rich  in 
lipase  but  devoid  of  trypsin,  were  equally  ineffective.  Fur- 
thermore, mixtures  of  liver  or  serum  lipase  and  trypsin  were 
incapable  of  causing  fat  necrosis.  Fresh  pancreatic  extracts 
from  fasting  dogs,  containing  lipase  but  almost  no  trypsin 
(which  in  fresh  extracts  is  still  in  the  form  of  inactive  trypsin- 
ogen),  produced  abundant  fat  necrosis,  whereas  after  the  tryp- 
sinogen  in  such  extracts  was  activated  by  enterokinase,  no  fat 

1  Jour.  Exper.  Med.,  1897  (2),  413. 

2  Contrib.  of  pupils  of  W.  H.  Welch,  Baltimore,  1900,  p.  859  :  Johns  Hopkins 
Hosp.  Kep.,  1900  (9),  859. 

3  Opie,  "  Diseases  of  the  Pancreas,"  Lippincott  1903,  p.  156 ;  Johns  Hopkins 
Hosp.  Bull.,  1902  (13),  117. 

*  It  yet  remains  to  be  seen  if  this  is  a  constant  occurrence  ;  and  also  if  the 
lipase  so  excreted  comes  from  the  pancreas,  forZeri  (II  Policlinico,  1905  (12), 
733  has  found  lipase  in  the  urine  in  hemorrhagic  nephritis  and  inflammation 
of  the  urinary  tract. 

5  Jour.  Med.  Research,  1903  (9),  70. 


FAT  NECROSIS  323 

necrosis  could  be  produced.  It  therefore  seems  certain  that 
trypsin  alone  cannot  produce  fat  necrosis,  and  that  the  decrease 
in  strength  of  lipase  in  a  pancreatic  extract  is  associated  with  a 
corresponding  decrease  in  power  to  produce  fat  necrosis.  But, 
on  the  other  hand,  lipase  of  liver  or  blood-serum  alone,  or 
when  mixed  with  trypsin,  will  not  produce  fat  necrosis.  The 
possibility  remains  that  pancreatic  lipase  is  different  from  liver 
or  serum  lipase,  and  can  by  itself  cause  fat  necrosis ;  more  prob- 
ably, however,  the  production  of  fat  necrosis  depends  upon  a 
double  action,  trypsin  causing  the  death  of  the  cells,  and  lipase 
splitting  the  fats.1  The  fatty  acids  alone  will  not  cause  necro- 
sis of  fat-cells,  and  it  was  shown  that  the  first  steps  in  the  pro- 
cess consist  of  a  necrosis  of  the  surface  endothelium  extending 
into  the  connective  and  fat  tissue ;  this  may  occur  in  a  few 
minutes,  while  evidence  of  fat-splitting  can  be  obtained  only 
after  about  three  hours,  and  the  splitting  occurs  only  in  cells 
that  have  already  become  necrotic ;  hence  the  fat-splitting  is 
not  the  cause  of  the  necrosis,  but  occurs  subsequent  to  the  necro- 
sis. After  about  four  hours  a  substance  appears  in  the  decom- 
posed fat  that  stains  with  hematoxylin,  which  is  probably 
calcium. 

Fat  necrosis  may  be  produced  by  any  means  that  will  cause 
the  escape  of  pancreatic  juice  from  the  natural  channels  within 
the  gland.  In  human  pathology  it  has  followed  trauma  and 
acute  infection  of  the  gland,  but  the  most  common  cause  is  prob- 
ably the  blocking  of  the  ampulla  of  Yater  by  gall-stones,  which 
permits  the  bile  to  back  up  into  the  pancreatic  duct,  where  it 
produces  an  acute  inflammation  of  the  pancreas  (Opie 2).  Flex- 
ner3  has  shown  that  it  is  the  bile  salts  that  cause  the  inflam- 
mation, and  also  that  this  effect  is  decreased  or  prevented  by 
the  presence  of  large  amounts  of  colloids.  As  a  result  of  injury 
by  bile  salts,  or  any  other  agent  that  produces  cell  death,  the 
dead  and  injured  cells  are  digested  by  the  pancreatic  juice  which 
then  makes  its  escape  into  the  surrounding  fat  tissue.  Wells' 
experiments  showed  that  the  lesions  of  fat  necrosis  may  be  pro- 

1  When  fat  tissue  dies  in  the  body  from  other  causes,  the  lipase  normally  con- 
tained within  the  fat  tissue  does  not  cause  the  changes  seen  in  fat  necrosis.   It  is 
possible,  therefore,  that  the  combining  of  newly  split  fatty  acids  by  the  alkali  of 
the  pancreatic  juice  is  responsible  for  the  formation  of  the  large  amount  of 
soaps  found  in  fat  necrosis.     Otherwise  we  might  expect  the  lipase  to  produce 
only  an  equilibrium,  and  that,  in  the  case  of  fat,  seems  to  exist  when  most  of 
the  substance  is  neutral  fat.     In  support  of  this  idea  I  found  that  strong  alka- 
lies injected  into  fat  tissue  sometimes  caused  changes  very  closely  resembling 
areas  of  fat  necrosis  in  the  early  stages. 

2  Bull.  Johns  Hopkins  Hosp.,  1901  (12),  182. 

3  Jour.  Exp.  Med.,  1906  (8),  167. 


324  RETROGRESSIVE  CHANGES 

duced  in  three  to  five  hours,  large  enough  to  be  visible  to  the  naked 
eye  ;  their  form  and  size  depend  solely  upon  the  area  of  fat  tissue 
exposed  to  the  action  of  the  pancreatic  juice.  The  process  pro- 
gresses for  but  a  few  hours,  the  extension  seeming  to  be  limited 
by  surrounding  leucocytes.  The  lesions  may  appear  at  remote 
points  in  the  thoracic  and  pericardial  cavities  or  in  the  sub- 
cutaneous tissues,  the  causative  agent  probably  being  carried  by 
the  lymphatic  vessels.  Fat  necrosis  itself  is  not  dangerous  to 
the  affected  organism,  the  associated  pancreatitis  (and  peritonitis) 
causing  all  the  symptoms.1  There  is  no  evidence  that  suffi- 
cient quantities  of  soaps  (which  are  toxic)  are  absorbed  from 
the  necrotic  areas  to  cause  appreciable  intoxication.  Apparently, 
however,  glycerine  is  absorbed  in  sufficient  quantities  to  appear 
in  the  urine,  for  on  this  basis  Cam  midge2  has  devised  a  method 
of  diagnosis  of  pancreatic  lesions  by  examining  the  urine  for 
glycerin,  the  value  of  which  Robson3  has  affirmed.  Healing 
follows  rapidly  in  case  of  recovery  ;  the  foci  may  disappear  as 
early  as  eleven  days  after  their  formation  (in  experimental 
animals). 

Self-digestion  of  the  pancreas  occurs  soon  after  death,  and 
the  pancreatic  juice  may  in  this  way  bring  about  a  postmortem 
fat  digestion  that  resembles  somewhat  the  intravital  fat  necrosis 
in  its  gross  appearances,4  and  Wells  found  that  the  same  changes 
might  be  produced  by  injecting  pancreatin  into  the  bodies  of 
dead  animals,  or  by  keeping  fat  tissue  in  pancreatin  solutions. 
Wulff  found  that  fatty  acids  were  demonstrable  by  Benda's 
method  in  the  pancreas  of  nearly  all  cadavers.  The  process 
differs  from  the  intra  vitam  form  in  being  less  sharply  circum- 
scribed, and  microscopically  by  the  absence  of  cellular  and  vas- 
cular reaction.  That  the  essential  changes  of  fat  necrosis  can 
be  produced  postmortem  is  final  proof  that  they  are  due  to 
enzymes,  rather  than  to  circulatory  or  cellular  action. 


(Arch.  klin.  Chir.,  1906  (78),  845)  considers  the  intoxication  of 
acute  pancreatitis  as  an  intoxication  with  trypsin,  which  can  be  checked  by 
antitrypsin.  Doberauer  (Beitr.  klin.  Chir.,  1906  (48),  456),  however,  looks 
upon  the  products  of  cellular  disintegration  as  the  source  of  the  intoxication. 
v.  Bergmann  (Zeit.  exp.  Path.  u.  Ther.,  1906  (3),  401)  states  that  the  toxicity 
is  not  due  to  either  the  enzymes  or  to  albumoses  ;  and  that  it  is  a  true  auto- 
intoxication which  can  be  prevented  by  previous  immunization  with  either 
pancreas  extracts  or  commercial  trypsin. 

2  Brit.  Med.  Jour.,  1904  (i),  776;  Lancet,  1904  (i),  782;  1906,  May  19. 

3  Lancet,  1904  (i\  779. 

*Chiari,  Zeit.  f.  Heilk.,  1896  (17),  69;  Pforringer,  Virchow's  Arch.,  1899 
(158),  126;  Liepmann,  ibid.,  1902  (169),  532;  Wulff;  Berl.  klin.  Woch.,  1902 
(39),  734. 


GANGRENE  325 


GANGRENE 

This  term  indicates  merely  that  certain  marked  secondary 
changes,  either  putrefaction  or  desiccation,  have  occurred  in 
necrotic  areas  of  some  size.  Hence  we  have  the  chemical 
changes  of  putrefaction  added  to  those  of  necrosis  in  the  case 
of  moist  gangrene,  whereas  in  dry  gangrene  nearly  all  the 
chemical  changes  are  brought  to  a  standstill  through  the  desic- 
cation. In  the  latter  it  is  only  at  the  line  of  demarcation,  where 
some  moisture  remains,  that  chemical  changes  still  go  on ;  these 
consist  chiefly  of  autolysis  of  the  dead  tissues,  and  also  of  their 
digestion  by  leucocytes,  which  results  eventually  in  the  sepa- 
ration of  the  dead  tissue  from  the  living ;  this  is  best  seen  after 
surface  burns,  carbolic-acid  gangrene,  etc. 

Moist  gangrene  is  accompanied  by  the  dual  action  of  the 
cellular  enzymes  and  of  the  putrefactive  organisms  that  are 
growing  in  the  dead  tissue,  and  as  a  result  such  tissue  con- 
tains all  the  innumerable  products  of  the  decomposition  of 
proteids  and  fats.  Thus  Ziegler  mentions  as  morphological 
elements  that  may  be  present  in  gangrenous  tissues :  Fat- 
needles,  the  so-called  "  margarin  "  crystals  (a  mixture  of  stearic 
and  palmitic  acids),  fine  acicular  crystals  of  tyrosin,  globules  of 
leucin,  rhombic  plates  of  triple  phosphate,  black  and  brown 
masses  of  pigment,  and  crystals  of  hematoidin.  In  the  sputum 
from  pulmonary  gangrene  crystals  of  fatty  acids  are  a  peculiarly 
characteristic  feature,  and  according  to  Schwartz  and  Kayser,1 
they  are  produced  by  the  action  of  bacteria  upon  fats,  rather 
than  by  the  lipolytic  enzymes  of  the  tissues  themselves.  In 
solution  we  also  have,  beyond  a  doubt,  all  the  substances 
formed  in  the  decomposition  of  proteids,  from  proteoses  and 
peptones  down  through  the  different  amino-acids  to  such  final 
products  as  ammonia  and  its  salts,  while  CO2  and  H2S  are 
abundantly  given  off.  In  addition  occur,  undoubtedly,  many  of 
the  ptomai'ns  which  are  formed  by  the  action  of  the  bacteria 
upon  the  amino-acids  derived  from  the  proteids.2 

If  the  necrotic  tissue  is  in  contact  with  living  tissue  over  a 
considerable  area,  enough  of  these  products  of  autolysis  and 
putrefaction  may  be  absorbed  to  cause  intoxication  (sapremia). 
At  the  same  time,  the  formation  of  such  large  quantities  of 
crystalloids  from  the  proteids  of  the  dead  tissue  leads  to  a 

1  Zeit.  klin.  Med.,  1905  (56),  111. 

2  An  interesting  observation  concerning  gangrene  of  the  lung  has  been  made 
by  Eijkman  (Cent.  f.  Bakt.,  Abt.  1,  1903  (35),  1),  who  found  in  this  condition 
bacteria  that  secrete  an  enzyme  dissolving  elastic  tissue. 


326  RETROGRESSIVE  CHANGES 

diffusion  of  water  into  this  area,  with  consequent  swelling,  and 
often  a  lifting  up  of  the  skin  in  the  form  of  blisters. 

Bmphysematous  gangrene,1  usually  produced  by  gas- 
forming  anaerobic  bacteria,  particularly  by  B.  aerogenes  cap- 
sulatus,  may  also  possibly  be  produced  by  B.  coli  communis  in 
diabetic  patients  in  whose  blood  and  tissues  there  may  occur 
sufficient  sugar  to  permit  of  gas-formation.  Hitschmann  and 
Lindenthal2  found  that  the  gas  produced  in  cultures  by  an 
anaerobic  organism  which  they  isolated  from  a  case  of  emphysem- 
atous  gangrene,  consisted  of  67.55  per  cent,  hydrogen,  30.62 
per  cent,  carbon  dioxide,  and  traces  of  ammonia  and  nitrogen; 
this  corresponds  to  the  statement  of  Welch  and  Nuttall  that  the 
gas  in  the  tissues  of  infected  animals  is  inflammable.  Dunham 3 
found  that  the  gas  produced  by  B.  aerogenes  capsulatus  in  cul- 
tures has  the  following  composition  :  Hydrogen,  64.3  per 
cent.;  carbon  dioxide,  27.6  per  cent.;  other  gases,  probably 
chiefly  nitrogen,  8.1  per  cent. 

RIGOR  MORTIS4 

This  topic  may  be  appropriately  considered  in  connection 
with  cell  death,  since  it  is  a  characteristic  change  occurring  after 
general  death.  All  forms  of  muscle,  striped,  smooth,  and  car- 
diac, undergo  this  change,  which  is  shown  by  a  shortening  and 
thickening  of  the  muscle,  which  also  becomes  opaque  and  hard. 
Rigor  mortis  begins  first  in  the  heart  muscle,  according  to 
Fuchs,5  but  it  is  generally  observed  first  in  the  eyelids,  then  in 
the  muscles  of  the  jaw,  from  which  point  it  proceeds  down- 
ward, although  the  upper  extremities  may  not  become  rigid 
before  the  lower.  The  time  of  onset  is  extremely  variable,  but 
the  following  general  rules  may  be  stated  :  All  conditions 
that  lead  to  excessive  muscular  metabolism,  with  its  resulting 
increase  in  the  acidity  of  the  muscle  fluids,  will  hasten  the 
onset  of  rigor  mortis  ;  thus,  people  killed  suddenly  during  violent 
activity  may  remain  almost  in  the  position  in  which  they  met 
death.  Acute  fevers,  strychnine  poisoning,  tetanus,  etc.,  cause 
likewise  a  rapid  onset  of  rigor,  which  may,  indeed,  appear 
almost  simultaneously  with  death,  or  even  before  the  heart  has 
stopped  beating.  When  a  healthy  individual  meets  death  with- 

1  Complete  literature  by  Fraenkel,  Ergebnisse  der  Pathol.,  1902  (8),  403 ; 
and  by  Welch,  Johns  Hopkins  Hosp.  Bull.,  1900  (11),  185. 

2  Quoted  by  Fraenkel. 

3  Johns  Hopkins  Hosp.  Bull.,  1897  (8),  68. 

*  Literature,  see  v.  Fiirth,  Ergeb.  der  Physiol.,  Abt.  1,  1902  (1),  110;  and 
references  cited  in  text. 

5Zeit.  f.  Heilk.,  1900  (21,  Path.  Abt.),  1. 


RIGOR  MORTIS  327 

out  previous  exertion,  rigor  does  not  usually  appear  for  four  or 
six  hours,  but  will  be  hastened  by  heat  and  retarded  by  cold. 
Death  from  hemorrhage  or  asphyxia  is  followed  by  a  slow  de- 
velopment of  the  rigor.  Under  ordinary  conditions  rigor 
usually  begins  between  the  first  and  second  hour  after  death 
and  is  complete  in  one  or  two  more  hours.1 

The  duration  of  rigor  mortis  also  is  influenced  by  many  fac- 
tors. In  general,  it  may  be  said  that  the  duration  is  in  direct 
relation  to  the  rapidity  of  onset,  and  also  to  the  musculature  of 
the  individual.  Therefore,  in  an  emaciated  individual  dying 
with  fever,  rigor  may  appear  and  disappear  again  within  two  or 
three  hours,  or,  indeed,  escape  observation  altogether.  The 
body  of  a  muscular  man  dying  from  accident  or  hemorrhage 
may,  on  the  other  hand,  show  rigor  for  two  or  three  weeks  if 
kept  in  a  cold  place.  Once  the  rigor  has  been  broken  by  force, 
it  does  not  again  return. 

Rigor  mortis  may  be  produced  even  before  death,  through 
poisons  (monobromacetic  acid,  quinine),  and  its  occurrence, 
even  postmortem,  does  not  necessarily  mean  that  the  muscle  is 
dead,  for  if  the  part  is  transfused  with  a  salt  solution  the 
rigor  may  be  removed,  and  the  muscle  will  then  be  found  to 
react  to  stimuli.  This  indicates  that  the  chemical  changes  of 
rigor  mortis  are  not  very  profound.2 

The  chemistry  of  the  changes  involved  in  rigor  mortis  has 
been  a  much-contested  problem.  Two  chief  doctrines  have 
been  supported :  one  that  rigor  was  not  essentially  different 
from  ordinary  muscular  contraction  except  in  degree,  and  per- 
haps due  to  a  loss  of  inhibition  to  contraction.  The  other 
looks  upon  it  as  a  coagulation  similar  to  the  coagulation  of  the 
blood ;  and  this  idea,  it  may  be  said,  has  had  the  most  general 
acceptance.  Briicke  in  1842  supported  this  view,  and  in  1859 
Kiihne  extracted  from  muscle  a  plasma  which  coagulated  like 
ordinary  blood  plasma.  The  proteid  which  formed  the  clot  is 
called  myosin,  and  its  coagulated  antecedent,  myosinogen. 

This  experiment  has  been  since  repeatedly  verified  and  am- 
plified, especially  by  v.  Fiirth  and  by  Halliburton,3  who  have 
separated  more  definitely  the  proteids  concerned  in  coagulation, 
and  found  them  to  be  globulins.  There  seem  to  be  two  :  one, 
coagulating  at  47°,  called  paramyosinogen  (Halliburton),  con- 
stitutes but  about  one-fifth  of  the  total  clotting  globulin,  and 

1  Rigor  mortis  may  develop  in  the  dead  fetus  while  in  the  womb,  but  it 
generally  disappears  within  five  or  six  hours.     Literature  by  Wolff,  Arch.  f. 
Gyn.,  1903  (68),  549 ;  Das,  Brit.  Jour,  of  Obstet.,  1903  (4),  545. 

2  See  Mangold,  Pfliiger's  Arch.,  1903  (96),  498. 

3  "  Chemistry  of  Muscle  and  Nerve, "  1904. 


328  RETROGRESSIVE  CHANGES 

passes  readily  into  the  insoluble  clot,  myosin  ;  the  other,  which 
coagulates  at  56°,  constitutes  the  remaining  four-fifths,  is  called 
myosinogen  (Halliburton),  or  myogen  (v.  Furth),  and  before  be- 
coming changed  into  myosin  it  passes  through  a  soluble  stage 
called  soluble  myogen-fibrin,  which  is  coagulated  at  the  remark- 
ably low  temperature  of  40°. 

By  analogy  with  fibrin- formation  we  should  expect  this 
clotting  also  to  be  brought  about  by  an  enzyme,  but  this  has 
not  been  proved.  Calcium  is  of  influence,  favoring  coagulation 
greatly,  but  its  presence  is  not  absolutely  essential  (v.  Furth). 
Of  particular  importance  is  the  acid  reaction  of  the  dead 
muscle.  Normal  muscle  is  amphoteric  when  at  rest,  but  when 
active  the  reaction  becomes  more  and  more  acid,  as  it  also  does 
when  the  circulation  is  shut  off,  and  hence  it  increases  greatly 
after  death.  The  acidity  is  due  chiefly  to  lactic  acid  (although 
the  neutral  phosphates  may  become  converted  into  acid  phos- 
phates in  the  presence  of  the  lactic  acid,  and  thus  seem  to  con- 
tribute to  the  acidity),  and  may  increase  in  twenty-four  hours 
after  death  by  from  6.7  to  12.8  c.c.  of  ^  acid  for  each  100 
grams  of  muscle  (v.  Furth l ).  The  same  author  found  that 
although  the  amount  of  acid  might  become  in  time  sufficient  to 
cause  coagulation  of  the  muscle  proteids  by  itself,  yet  actually 
rigor  mortis  appears  before  the  acidity  has  reached  any  such 
degree.  We  may  conclude  that  the  acidity  of  the  muscle 
hastens  the  clotting,  possibly  by  favoring  some  undemonstrated 
coagulating  enzyme,  and  in  late  stages  it  may  become  so  great 
as  to  precipitate  the  proteids  that  are  not  involved  in  the  clot- 
ting. This  readily  explains  why  the  time  of  appearance  of 
rigor  is  so  modified  by  the  amount  of  muscle  metabolism  before 
death.  It  is,  indeed,  possible  to  produce  rigor  in  living  animals 
by  transfusing  a  limb  with  slightly  acid  salt  solution,2  and  in 
strychnine-poisoning  the  muscular  spasm  may  pass  impercep- 
tibly into  rigor  mortis. 

In  all  probability  the  disappearance  of  rigor  mortis  depends 
upon  beginning  autolysis  of  the  clot  by  the  intracellular  pro- 
teases of  the  muscle,  which  act  best  in  an  acid  medium.  It  is 
improbable  that  the  degree  of  acidity  ever  becomes  so  high  that 
the  myosin  is  redissolved  through  a  conversion  into  acid  albumin 
(syntonin),  as  was  formerly  supposed. 

1  Hofmeister's  Beitr.,  1903  (3),  543. 

2  The  hardness  of  a  limb  from  which  the  blood-supply  has  been  shut  off  by 
thrombosis  or  embolism,  and  also  much  of  the  cramp-like  pain,  is  probably  due 
to  rigor  mortis  in  the  muscles  caused  by  acid  formation  under  conditions  of 
sub-oxidation. 


CLOUDY  SWELLING  329 

CLOUDY  SWELLING  i 

The  characteristic  appearance  of  organs  the  seat  of  cloudy 
swelling,  which  is  frequently  likened  to  a  "  scalded  "  appearance, 
suggests  that  the  change  consists  in  a  coagulation  of  the  cell 
proteids,  which  idea  is  supported  by  the  similarity  of  the  micro- 
scopic changes  observed  in  the  cells  and  the  earliest  microscopic 
changes  observed  in  cells  after  heating  gently  to  about  their 
maximum  thermal  point.  On  the  other  hand,  the  granules  in 
cloudy  swelling  are  generally  described  as  being  soluble  in 
dilute  acetic  acid  and  dilute  KOH,  which  indicates  that  they 
are  not  the  result  of  ordinary  heat  coagulation.  If  we  bear  in 
mind,  however,  that  cloudy  swelling  probably  does  not  repre- 
sent one  single  change,  it  may  be  possible  to  arrive  at  some 
understanding  of  the  chemical  changes  that  occur  in  the  process. 
Albrecht 2  considers,  with  good  reason,  that  we  may  have  a 
granular  appearance  of  cells  which  is  simply  an  exaggeration 
of  the  normal  granular  structure,  and,  although  it  may  be 
observed  in  tissues  moderately  affected  by  toxins,  or  in  starva- 
tion, or  in  transitory  anemia,  the  change  is  still  to  be  looked 
upon  as  little  more  than  physiological  in  reponse  to  stimuli  and 
overwork.  Such  a  "  cloudy  swelling  "  may  also  occur  in  cells 
in  the  beginning  of  autolysis,  or  simply  under  the  influence  of 
salt  solution.  If  the  injury  is  greater,  however,  as  in  profound 
sepsis,  or  extreme  local  anemia,  the  granules  become  coarser, 
less  soluble  in  acetic  acid  and  KOH,  and  droplets  resembling 
"  myelin  "  make  their  appearance.  If  the  injury  is  still  more 
severe,  true  coagulation  of  the  granules  occurs,  and  they  become 
insoluble,  the  fatty  droplets  become  more  prominent,  and  the  cell 
reaches  a  condition  that  may  with  propriety  be  termed  necrosis 
or  fatty  degeneration,  or  both.  There  is  no  very  sharp  line 
separating  necrosis  and  cloudy  swelling,  especially  if  we  con- 
sider only  the  changes  in  the  cytoplasm.  In  the  earliest  stages 
the  granules  are  perhaps  due,  in  some  cases,  to  simple  aggre- 
gation of  the  colloids,  without  the  development  of  a  true  coagu- 
lation, and  so  the  granules  are  still  soluble.  Possibly  bacterial 
toxins  may  also  cause  soluble  precipitates,  but  this  does  not 
appear  to  have  been  established.  Halliburton  has  shown  that 
temperatures  that  may  be  reached  in  high  fevers  can  cause  tur- 
bidity in  solutions  of  cell  proteids,  and  hence  heat  precipitation 
may  be  partly  responsible  for  the  turbidity  of  cells  in  cloudy 
swelling,  but  it  is  doubtful  if  the  granules  thus  formed  would 
be  soluble  in  acetic  acid. 

1  Review  of  general  features  by  Landsteiner,  Ziegler's  Beitr.,  1903  (33),  237. 

2  Verb.  Deut.  Path.  Gesell.,  1903  (6),  63. 


330  RETROGRESSIVE  CHANGES 

We  may  speak  with  more  assurance  concerning  the  swelling 
of  the  cell,  and  attribute  it  to  an  increase  in  the  osmotic  pres- 
sure of  the  cell  contents,  with  consequent  taking  up  of  water. 
The  rise  in  osmotic  pressure  is  probably  due  to  abnormally 
rapid  splitting  of  proteids  with  incomplete  oxidation  of  the 
substances  formed,  which  results  in  formation  of  many  crystal- 
loid molecules  with  high  total  osmotic  pressure,  from  a  smaller 
number  of  colloid  molecules  with  almost  no  osmotic  pressure.  It 
has  frequently  been  shown  that  the  cell-walls  do  not  lose  their 
semipermeable  character  until  the  death  of  the  cell  occurs  ; 
hence  in  cloudy  swelling  water  diffuses  in  much  more  rapidly 
than  the  crystalloids  can  diffuse  out,1  causing  a  hydropic  swell- 
ing. This  hypothesis  is  supported  by  the  observations  of 
Cesaris  Demel,2  who  found  that  by  modifying  the  osmotic  con- 
ditions of  the  cells,  particularly  epithelial  cells,  he  could  closely 
reproduce  many  of  the  characteristic  features  of  parenchymatous 
degeneration.  It  is  possible,  also,  that  too  high  concentration 
of  crystalloids  within  the  cells  may  be  a  factor  in  the  precipita- 
tion of  the  cell  colloids.  In  view  of  the  fact  that  in  the  earli- 
est stages  of  autolysis  histologic  and  microscopic  changes  closely 
resembling  those  of  cloudy  swelling  are  pronounced,  and  that 
organs  the  seat  of  cloudy  swelling  notoriously  undergo  autolysis 
with  extreme  rapidity  after  death,  we  may  also  consider  that 
this  process  is  possibly  in  part  responsible  for  the  change  of 
ordinary  intra  vitam  cloudy  swelling.  The  appearance  of  fine 
granules  of  lipoid  substance  (myelin  or  "  protagon  "  (?) )  in  cells 
during  autolysis  and  during  cloudy  swelling  is  cited  by  Orgler 3 
in  support  of  this  idea,  and  he  found  by  chemical  analysis  of 
organs  showing  cloudy  swelling  that  there  is  definite  evidence 
of  autolytic  decomposition  of  the  proteids  and  an  increase  in 
the  water  content.4  Landsteiner,  through  his  studies  of  cloudy 
swelling  in  human  material  also  came  to  the  conclusion  that 
autolysis  is  an  important  element  in  its  production. 

"Waxy"  degeneration  of  muscles,  although  usually  result- 
ing from  the  action  of  toxic  substances,  is  entirely  different  from 
cloudy  swelling,  in  that  the  cytoplasm  becomes  homogeneous 
and  not  granular.  Dr.  A.  P.  Mathews  has  suggested  to  me, 
as  a  possible  explanation,  that  the  change  is  allied  to  the  action 
of  acids  upon  fibrin,  which  causes  the  fibrin  to  swell  up  and 
become  homogeneous.  As  we  know  that  abundant  acid 

1  See  introductory  chapter  concerning  osmosis  ;  also  discussion  of  edema. 

2Lo  Sperimentale,  1905  ;  Cent.  f.  Path.,  1905  (16),  613. 

3  Virchow's  Arch.,  1904  (176),  413. 

*  Verb.  Deut.  Path.  Gesell.,  1903  (6),  76. 


CLOUDY  SWELLING  331 

formation  goes  on  in  muscle-cells  under  pathological  conditions, 
this  explanation  seems  to  have  considerable  value.  The  results 
of  some  preliminary  experiments  that  I  have  performed  support 
this  hypothesis.1 

Summary. — Putting  all  these  facts  together,  we  may  look 
upon  the  term  cloudy  swelling  as  applying  to  many  different 
sorts  of  processes  which  may  be  caused  by  many  different  factors, 
the  common  features  being  the  precipitation  or  the  coagulation 
of  part  of  the  dissolved  cell  proteids  (often  with  the  separation 
of  the  intracellular  fat  from  the  proteids,  so  that  it  becomes 
microscopically  visible)  and  the  imbibition  of  water. 

"Hydropic  degeneration"  may  be  properly  considered  as 
differing  from  cloudy  swelling  chiefly  in  the  excessive  promi- 
nence of  the  absorption  of  water. 

1  Muscles  showing  the  reaction  of  degeneration  have  been  analyzed  by 
Eumpf  and  Schumm  (Deut.  Zeit.  f.  Neryenheilk.,  1901  (20),  445),  who  found  a 
great  increase  in  the  fatty  matter,  which  was  about  fifteen  times  the  normal 
amount.  The  muscle,  deducting  the  fat,  showed  a  loss  of  solid  matter  and  an 
increase  of  water ;  sodium  and  calcium  were  increased,  potassium  decreased. 


CHAPTER    XIV 

RETROGRESSIVE  PROCESSES  (CONTINUED) 

Fatty*  Amyloid,  Hyaline,  Colloid,  and  Glycogenic  Infiltration 
and  Degeneration 

FATTY  METAMORPHOSIS 

IN  1847,  in  the  first  number  of  his  Archiv,  Virchow 
divided  the  forms  of  fatty  changes  that  may  occur  in  patholog- 
ical conditions  into  two  groups — "  infiltration  "  and  "  degenera- 
tion " — a  division  that  has  since  become  classical.  By  infiltra- 
tion he  indicated  the  excessive  accumulation  of  fat  in  the  cells 
in  the  form  of  large  droplets,  without  destruction  of  the  nucleus 
or  irreparable  damage  to  the  cells,  and  by  the  use  of  the  term 
infiltration  he  implied  his  belief  that  the  fat  entered  the  cell 
from  without.  When  the  fat  remained  in  the  form  of  fine  drop- 
lets and  the  cell  became  much  disintegrated,  Virchow  considered 
that  the  fat  was  derived  from  the  breaking  down  of  the  cell 
proteids,  and  hence  the  process  was  considered  to  be  a  fatty 
degeneration  of  the  protoplasm.  Since  that  time  scarcely  any 
other  subject  in  pathology  has  been  more  warmly  discussed 
than  that  of  the  origin  of  the  fat  in  fatty  degeneration,  and  an 
appalling  amount  of  literature  has  accumulated  concerning  the 
question  involved.  It  will  be  impossible  to  give  more  than  the 
essential  facts  that  have  been  developed,  referring  the  reader  for 
the  full  details  of  the  discussion  and  evidence  to  the  numerous 
compilations  of  literature,  particularly  those  of  Rosenfeld,1  and 
to  the  original  articles  cited  in  the  text. 

PHYSIOLOGICAL   FORMATION  OF   FAT 

Concerning  the  normal  formation  of  fat  we  may  summarize 
the  evidence  as  follows  : 

(1)  A  large  proportion  of  the   fat  of  the  body  comes  from 

luFat  Formation."  Ergebnisse  der  Physiol.,  Abt.  1,  1902  (1),  651 ;  ibid., 
1903  (2),  50.  Also  see  discussion  in  the  Verb.  Deut.  Path.  Gesell.,  1904  (6), 
37-108,  and  the  review  by  Leathes  in  his  "  Problems  in  Animal  Metabolism ," 
1906,  pp.  71-121 .  Concerning  modern  theories  of  role  of  lipase  in  fat  metabolism 
see  Chap.  iii.  Other  reviews  of  literature  on  pathological  fat  formation  by 
Christian,  Johns  Hopkins  Hosp  Bull.,  1905  (16),  1  ;  Herxheimer,  Ergebnisse 
der  Pathol.,  1902  (8),  625;  Lohlein,  Virchow's  Arch.,  1905  (180),  1  ;  Pratt, 
Johns  Hopkins  Hosp.  Bull,  1904  (15),  301  (particular  reference  to  heart). 
Later  references  of  importance  cited  in  the  text. 
332 


PHYSIOLOGICAL  FORMATION  OF  FAT  333 

the  fat  taken  in  the  food,  as  also  does  the  fat  of  the  milk. 
This  can  be  shown,  as  Rosenfeld  particularly  demonstrated,  by 
starving  an  animal  until  it  is  as  free  from  fat  as  possible,  then 
feeding  with  a  large  amount  of  some  fat  that  is  of  a  type  dif- 
ferent from  that  normally  found  in  the  animal ;  the  new  fat 
that  is  then  laid  up  in  the  fat  depots  of  the  animal  will  partake 
of  the  characters  of  the  fat  given  in  the  food.  In  case  the 
animal  is  lactating,  the  milk-fat  will  also  resemble  the  fat  of 
the  food.1  As  a  matter  of  fact,  the  body  fat  is  not  of  constant 
composition,  even  in  the  same  individual ;  it  varies  greatly  with 
age,  having  much  less  olein  in  infancy  than  in  later  years, 
varying  somewhat  in  composition  in  the  different  fat  depots  in 
the  same  body,  and  apparently  being  more  or  less  modified  by 
diet. 

(2)  Fat  may  also  be  formed  from  carbohydrates.     According 
to  Rosenfeld,  this  fat  differs  from  the  fat  formed  on  mixed  diet 
in  having  less  olein  in  proportion  to  the  palmitin  and  stearin, 
and  it  is  deposited  particularly  in  the  subcutaneous  and  mesen- 
teric  tissues  rather  than  in  the  liver.     Man  does   not  seem  to 
form  fat  readily  from  carbohydrates,  but  rather  burns   them   to 
protect  his  proteids ;  on  the  other  hand,  swine  and  geese  readily 
form  fat  from  carbohydrates.       As  the  fatty  acid  radicals  of 
ordinary  fat  (C^H^O^  C16H32O2,  C18H34O2)  are  much  larger  than 
the  carbohydrate  radicals,  a  process  of  synthesis  must  be  in- 
volved in  the  formation  of  fat  from  carbohydrates.2 

(3)  Proteids  are  a  possible  source  of  fat,  but  it  has  not  been 
established  that  they  are  either  a  common  or  an  important 
source  of  fat  in  either  physiological  or  pathological  conditions, 
or,  indeed,  that  they  really  ever  do  form  fat.     Upon  this  state- 
ment rests  our  present  tendency  to  refute  the  long-cherished 
conception  of  fatty  degeneration  as  a  true  degeneration  of  cell 
proteids  into  fat,  as  suggested  by  Virchow.     This  view  was 
supported  by  the  earlier  work  of  Voit  and  his  school,  who  be- 
lieved that  they  had  demonstrated  that  animals  could  form  fat 
from  proteid  food,  and  their  work  was  for  a  long  time  accepted 
as  correct.     Later  Pfliiger  and  his  pupils  pointed  out  what 
seem    to    have    been   essential    errors   in   these   investigations, 
and,  after  much  discussion  and  experimentation,  the  majority 

1See  Engel,  Zeit.  physiol.  Chera.,  1905  (44),  353.  Thiemich  (Jahrb.  f. 
Kinderheilk.,  1905  (61),  174)  has  also  found  evidence  that  the  fat  of  the  fetus 
is  transported  from  the  fat  depots  of  the  mother. 

2  This,  Magnus-Levy  suggests,  may  he  accomplished  through  lactic  acid 
which  is  formed  from  sugar,  and  then,  after  reduction  to  an  aldehyde,  several 
of  these  molecules  are  combined  into  the  higher  fatty  acid.  See  Leathes,  loc. 
cit.,  p.  82. 


334  RETROGRESSIVE  PROCESSES 

of  physiologists  now  support  the  view  advanced  in  the  sentence 
opening  this  paragraph.  Since  proteids  contain  carbohydrate 
groups,  and  since  fats  can  be  formed  from  carbohydrates,  the 
possibility  of  the  formation  of  fats  from  the  proteids  in  this 
indirect  way  cannot  be  denied.  It  is  also  possible  that  the 
nitrogen-containing  groups  may  be  split  out  of  the  amino-acids 
of  the  proteid  molecule,  and  that  the  non-nitrogenous  residues 
can  then  be  built  up  into  fatty  acid  molecules  as  large  as  the 
molecules  of  stearic,  palmitic,  and  oleic  acids ;  but  we  have  no 
proof  that  either  of  these  processes  occurs  in  the  normal  cell 
or  in  the  cell  that  is  undergoing  degeneration. 

PATHOLOGICAL  FAT  ACCUMULATION 

For  a  long  time  fatty  degeneration  was  looked  upon  as  one 
of  the  chief  evidences  that  fat  was  formed  directly  from  proteid, 
for  the  cell  protoplasm  seemed,  morphologically,  to  be  changed 
directly  into  fat  in  this  process.  Additional  support  was  also 
claimed  from  the  supposed  increase  in  fat  in  the  ripening  of 
cheese ;  from  the  formation  of  abundant  fat  by  maggots  living 
in  fat-poor  blood  or  fibrin  ;  and  by  the  apparent  conversion  of 
proteids  into  fatty  acids  and  soaps  in  the  postmortem  change, 
adipocere.  But  it  has  now  been  well  established  that  there  is 
no  true  conversion  of  proteid  into  fat  in  the  fatty  degeneration 
produced  experimentally  by  poisoning  with  phosphorus,  etc.,1 
and  the  other  supposed  instances  of  fat-formation  above  cited 
have  been  discredited  by  various  methods  which  it  will  not  serve 
our  purpose  to  discuss  here,  beyond  mentioning  that  one  of  the 
chief  sources  of  error  lies  in  the  fact  that  many  fungi  and 
bacteria 2  can  form  fat  from  proteid. 

It  having  been  rendered  probable  that  fat  was  not  formed 
by  disintegration  of  the  proteid  of  the  degenerating  cells,  it 
remained  to  determine  what  the  source  of  the  fat  observed  in 
the  cells  under  pathological  conditions  might  be,  and  this  part 
of  the  problem  has  been  largely  cleared  up  by  Rosenfeld.  This 
investigator  proceeded  as  follows  :  Animals  were  starved  until 
they  were  extremely  poor  in  fat,  then  fed  upon  easily  identified 
foreign  fats,  such  as  mutton  tallow  (which  has  a  high  melting- 
point  and  can  combine  with  little  iodin)  or  linseed  oil  (which 
has  a  low  melting-point  and  can  combine  with  much  iodin). 
The  animals  under  these  conditions  laid  up  in  their  fat  depots, 
including  the  liver  as  well  as  the  subcutaneous  tissues,  large 

1  See  Taylor,  Jour.  Exp.  Med.,  1899  (4),  399. 

2  See  Beebe  and  Buxton,  Amer.  Jour,  of  Physiol.,  1905  (12),  466  ;  Slosse, 
Arch.  Internal.  Physiol.,  1904  (1),  348. 


PATHOLOGICAL  FAT  ACCUMULATION  335 

quantities  of  these  foreign  fats.  By  starving  again  for  a  few 
days  the  foreign  fat  was  removed  from  the  liver,  leaving  still  a 
large  amount  in  the  other  storehouses,  and  the  animals  were  then 
poisoned  with  phosphorus  or  other  poisons  that  cause  a  typical 
fatty  degeneration  of  the  liver  and  other  viscera.  When  the 
fat  was  extracted  from  the  fatty  liver  of  these  animals,  it  was 
found  that  the  new  fat  that  had  appeared  in  the  liver  during 
the  process  was  not  normal  dog  fat  (which  it  should  have  been 
if  formed  by  degeneration  of  the  cell  proteids),  but  was,  in  part, 
of  the  same  type  as  the  foreign  fat  which  the  animals  had  deposited 
in  their  subcutaneous  tissues  and  other  fat  storehouses.  Further- 
more, it  was  found  that  animals  starved  to  an  extremely  low 
fat  content  do  not  develop  the  typical  fatty  liver  of  phosphorus- 
poisoning,  a  fact  which  Lebedeif  had  already  noted  in  a  case  of 
phosphorus-poisoning  in  an  emaciated  patient.  Therefore,  it 
seemed  evident  that  the  fat  accumulating  in  the  liver  during  fatty 
degeneration  is  not  derived,  as  Virchow  thought,  through  a  trans- 
formation of  cell  proteids  into  fat,  but  rather  is  an  infiltrated  fat 
brought  in  the  blood  from  the  fat  deposits  of  the  body  to  the  disin- 
tegrating organ.  This  work  has  since  been  corroborated  and 
extended  by  many  observers,  and  its  correctness  can  now  hardly 
be  questioned.1  "  Fatty  degeneration,"  therefore,  differs  from 
"  fatty  infiltration  "  chiefly  in  the  fact  that  in  the  former  the 
process  is  associated  with  serious  injury  to  the  cell,  caused  by 
the  action  of  toxins  or  loss  of  nutrition,  while  in  the  latter  the 
cell  is  not  seriously  injured  and  is  capable  of  returning  to  its 
normal  condition  whenever  the  fat  is  removed.2 

Fatty  "  Degeneration  "  without  Infiltration. — By 
showing  that  the  new  fat  in  fatty  livers  is  infiltrated  fat, 
Rosenfeld  did  not  entirely  clear  up  the  subject,  for,  in  the 
course  of  his  analyses  of  organs  that  were  macro-  or  micro- 
scopically the  seat  of  fatty  degeneration,  he  found  that  there  is 
not  always  any  correspondence  between  the  amount  of  fat  that 
seems  to  be  present,  as  determined  by  microscopic  methods,  and 
the  amount  that  chemical  analysis  shows  to  be  present.  This 

^chwalbe  (Verb,  der  Deut.  Path.  Gesell.,  1903  (6),  71)  claims  that  in  a 
similar  way  iodin  compounds  of  fat  can  be  demonstrated  to  be  transported  into 
the  fatty  organs.  His  analyses  were  merely  qualitative,  and  by  quantitative 
determinations  I  was  unable  to  corroborate  his  results  (Zeit.  f.  physiol.  Chem., 
1905  (45),  412). 

2  A  striking  proof  of  the  lack  of  injury  associated  with  fatty  infiltration  is 
shown  by  the  fatty  infiltration  frequently  seen  in  the  liver,  especially  of  alco- 
holics, in  which  it  may  be  difficult  to  find,  microscopically,  any  cell  cytoplasm 
because  of  the  fat,  the  tissue  looking  like  fatty  areolar  tissue ;  and  yet  there 
may  be  no  clinical  evidence  whatever  that  the  liver  function  has  been 
impaired  by  the  process. 


336  RETROGRESSIVE  PROCESSES 

is  particularly  true  of  the  kidney.  Thus,  the  amount  of  fat 
present  in  normal  kidneys  (dog)  was  found  to  vary  between 
18.5  per  cent,  and  29.12  per  cent,  of  the  dry  weight,  the 
average  being  21.8  per  cent. ;  whereas,  after  producing  a  typi- 
cal "  fatty  degeneration "  by  means  of  phosphorus  and  other 
poisons,  the  fat  content  was  still  found  to  be  between  16.9 
per  cent,  and  22.6  per  cent.1  In  all  instances  the  amount 
of  fat  in  kidneys  showing  typical  fatty  degeneration  under  the 
microscope  was  found  equal  to  or  less  than  the  normal  amount — 
it  was  never  increased.  The  same  conditions  were  found  to 
obtain  in  human  kidneys  that  showed  fatty  metamorphosis. 
Microscopic  examination  of  specimens  stained  with  the  specific 
fat  stains,2  therefore,  gives  no  indication  of  the  amount  of  fat 
contained  in  a  degenerated  kidney.  A  pathologic  kidney  con- 
taining 16  per  cent,  of  fat  (18  per  cent,  is  about  the  average 
amount  of  fat  in  normal  human  kidneys)  may  show  extreme 
"  fatty  degeneration "  under  the  microscope,  whereas  another 
kidney  may  contain  as  much  as  23  per  cent,  of  fat,  yet  not 
show  any  fat  whatever  by  staining  methods. 

The  explanation  of  this  remarkable  discrepancy  is  as  follows  : 
Every  tissue  and  organ  seems  to  contain  a  greater  or  less  amount 
of  fat,  varying  from  5  per  cent,  to  20  per  cent,  of  the  total  dry 
weight  of  the  organ  in  the  case  of  most  of  the  important  tissues, 
yet  this  fat  is  usually  held  in  such  a  form  that  it  cannot  be  stained 
by  any  stains  available  for  the  purpose.  Thus  in  the  kidneys, 
as  before  remarked,  we  may  have  as  much  as  23  per  cent,  of  fat 
present  and  yet  be  entirely  unable  to  stain  any  of  it.  The 
greater  part  of  this  fat  seems  to  be  essential  to  the  cell,  for  it 
cannot  be  removed  by  the  most  extreme  starvation  ;  e.  g.,  the 
liver  of  the  most  emaciated  dogs  may  contain  10  per  cent,  to 
20  per  cent,  of  fatty  substances.  Furthermore,  the  same  resistance 

1  Concerning  the  normal  intracellular  fats  see  introductory  chapter. 

2  Fat-staining  involves   several   principles  of  interest   in  this  connection. 
Osmic  acid  (OsO4),  the  longest  used  for  this  purpose,  is  reduced  to  OsO2  by 
oleic  acid,  imparting  a  black  or  dark-brown  color  to  the  fat ;  but  it  does  not 
stain  saturated  fatty  acids,  such  as  palmitic  or  stearic  acid.     Thus,  Christian 
found  in  pneumonic  exudates  fat  that  stained  by  other  methods  but  not  by 
osmic  acid,   apparently   because   it   contained    no   oleic    acid    (Jour.    Med. 
Research,  1903  (10),  109).     Sudan  III  and  scarlet  R  (fat  ponceau)  are  two 
synthetic  dyes  which  stain  fat  in  a  purely  physical  way,  entering  and  remain- 
ing in  the  fat-droplets  because  they  are  much  more  soluble  in  fat  than  they 
are  in  water  or  alcohol.     (Fully  discussed  by  Michaelis  (who  introduced  scar- 
let R)   in  Virchow's  Arch.,  1901   (164),  263;  and  by  Mann,  "Physiological 
Histology,"  p.  306.)     These  stains  have  the  advantage  of  staining  all  sorts  of 
fats  and  not  staining  other  substances  that  may  reduce  osmic  acid.     Fatty 
acids  and  soaps  may  be  stained  with  copper  acetate,  which  forms  a  green  cop- 
per salt,  and  thus  be  distinguished  from  fats  (Benda,  Virchow's  Arch.,  1900 
(161),  194. 


PATHOLOGICAL  FAT  ACCUMULATION  337 

is  shown  by  part  of  the  fat  to  extraction  with  ether.  A  certain 
proportion  of  the  fat  can  be  extracted  readily  in  twenty-four 
hours  or  less  by  ether,  but  after  this  time  no  more  can  be  made  to 
leave  the  tissues.  Apparently  the  rest  of  the  fat  is  held  in  a 
combination  (which  seems  to  be  chemical  rather  than  physical) 
that  is  insoluble  in  ether.  By  digesting  the  tissue  for  a  short 
time  by  pepsin,  however,  the  rest  of  the  fat  becomes  freed  (sug- 
gesting that  it  is  the  proteids  with  which  it  is  combined),  so  that 
it  can  then  be  readily  dissolved  out  in  ether.1  We  see,  there- 
fore, that  much  of  the  fat  of  normal  cells  is  so  firmly  combined 
that  it  cannot  be  dissolved  in  ether,  and  under  normal  conditions 
all,  or  nearly  all,  of  it  cannot  be  stained.  (This  applies  partic- 
ularly to  the  parenchymatous  organs ;  the  fat  of  the  areolar 
tissue  is  all  readily  extracted — Taylor.)  But  when  pathological 
changes  in  the  cells  result  in  decomposition  of  the  cell  proteid 
through  autolysis,  part  of  this  normally  invisible  fat  is  set  free, 
and,  becoming  visible,  produces  the  so-called  "  fatty  degenera- 
tion." This  explains  the  observations  of  Rosenfeld,  cited 
above,  that  kidneys  may  show  much  fat  to  the  naked  eye  and 
microscopically,  when  they  actually  contain  even  less  than  nor- 
mal amounts  of  fat.  Taylor2  advanced  this  explanation,  and 
supported  it  experimentally  by  showing  that  during  fatty  degen- 
eration this  protected  fat  actually  is  liberated,  some  two-thirds 
becoming  ether-soluble  in  an  experiment  performed  with 
phosphorus-poisoned  frogs.  As  further  support  may  be  men- 
tioned the  fact  that  organs  undergoing  experimental  autolysis 
show  microscopically  an  apparently  typical  fatty  degeneration, 
although  analyses  show  that  no  actual  increase  in  fat  occurs.3 

Relation  of  Anatomical  to  Chemical  Changes. — 
From  the  facts  brought  out  in  these  various  experiments  we 
must  consider  that  the  anatomically  established  condition  of 
"fatty  degeneration"  represents  either  or  both  of  two  con- 
ditions :  (1)  It  may  result  from  an  increase  in  the  normal 
quantity  of  fat  in  an  organ  undergoing  parenchymatous  degen- 
eration, through  an  infiltration  of  fat  from  the  outside ;  this  is 
particularly  true  of  the  fatty  degeneration  of  the  liver ;  (2)  or 
there  may  be  no  increase  in  the  total  amount  of  fat,  but  the 

1  Chloroform   will   separate    this  fixed  fat  from  the  tissues ;   and   alcohol- 
hardened  tissues  hold  much  less  of  the  fixed  fat  than1  do  dried  tissues. 

2  Jour.  Med.  Research,  1903  (9),  59. 

3Kraus,  Arch.  exp.  Path.  u.  Pharm.,  1886  (22),  174;  Siegert,  Hofmeister's 
Beitr.,  1901  (1),  114.  Waldvogel  (Virchow's  Arch.,  1904  (177),  1),  however, 
claims  that  the  "  protagon  "  and  "  jecorin  "  increase  in  autolyzing  organs,  while 
the  lecithin  decreases,  and  believes  that  proteids  may  indirectly  give  rise  to 
fat.  There  are  numerous  questionable  features  concerning  these  results,  and 
they  cannot  be  considered  as  final. 

22 


338  RETROGRESSIVE  PROCESSES 

invisible  fat  becomes  visible  through  autolysis  of  the  cell  pro- 
teids.  (3)  Finally,  of  course,  both  factors  may  occur  together. 
Of  these  various  forms,  in  only  the  first  and  last  can  we  properly 
consider  the  organ  "  fatty,"  and  the  form  that  will  occur  seems 
not  to  depend  upon  the  cause  of  the  cell  injury,  but  rather 
upon  the  organ  under  consideration.  In  a  study  of  the  relation 
of  the  morphological  to  the  chemical  changes  Rosenfeld  1  arrived 
at  the  following  results  : 

Normal  human  hearts  contain,  on  an  average,  15.4  per  cent, 
of  fat ;  the  hearts  showing  fatty  degeneration  contain  20.7  per 
cent.,  on  an  average.  The  pancreas,  which  normally  contains 
15.8—17.4  per  cent,  of  fat,  also  contains  an  increased  amount  of 
fat  when  showing  fatty  degeneration.  The  liver,  however,  takes 
on  by  far  the  greatest  amount  of  fat  after  "  steatogenetic  "  poi- 
sons, and  the  microscopic  picture  gives  a  very  good  approxi- 
mation of  the  amount  of  fat  it  contains.2  Apparently  in  these 
organs  any  excessive  fat  above  the  normal  is  observable  micro- 
scopically, although  the  normal  fat  content  is  not,  and  only  in 
these  three  organs  could  Rosenfeld  find  an  actual  increase  in  fat 
after  poisoning  with  phosphorus,  etc.  It  would  seem,  on  the 
other  hand,  that  there  is  not  often  a  real  increase  in  the  fat 
content  of  the  "fatty"  kidney.3  Normal  spleen  contains  14.2 
per  cent,  of  fat,  and  lung  17.3  per  cent.,  but  in  both, "  fatty  degen- 
eration "  results  in  a  lowering  of  this  quantity.  Degenerations 
in  the  nervous  tissue,  which  Yirchow  considered  the  best  evi- 
dence of  the  conversion  of  protoplasm  into  fat,  also  show  a  marked 
decrease  in  fat,  and  voluntary  muscle  shows  no  increase  in  the 
normal  quantity  after  poisoning.  In  general,  these  experiments 
support  the  contention  of  Taylor  concerning  the  disclosure  of  the 
invisible  fat  through  autolysis.4 

1  fieri,  klin.  Woch.,  1904  (41),  587. 

2  In  fatty  livers  in  phosphorus-poisoning  the  amount  of  fat  may  reach  75 
per  cent,  of  the  dry  weight.     Accompanying  the  fat  increase  are  increase  in 
water  and  a  relative  or  absolute  decrease  in  proteids,  probably  due  to  cell  autol- 
ysis.     In  acute  yellow  atrophy  a  similar  decrease  in  proteid  occurs,  but  without 
an  increase  in  fat.     (See  v.  Starck,  Deut.  Arch.  klin.  Med.,  1884  (35),  481.) 

3 This  is  contradicted  by  Landsteiner  and  Mucha  (Cent.  f.  Path.,  1904  (15), 
752)  and  by  Lohlein  (Virchow's  Arch.,  1905  (180),  1)  and  Rosenthal  (Deut. 
Arch.  klin.  Med.,  1903  (78),  94),  but  is  supported  by  Orgler  (ibid.,  1904  (176), 
413).  See  also  the  recent  studies  by  Rosenfeld  on  "the  effects  of  various 
steatogenic  poisons  on  different  organs,  in  Arch.  f.  Exp.  Path.  u.  Pharm.,  1906 
(114),  179  and  344.  It  is  probable  that  the  truth  lies  between  the  opposing  views, 
namely,  the  kidney  may  under  some  conditions  take  up  fat  from  the  blood,  but  it 
does  so  to  a  much  less  extent  than  the  liver,  and  it  may  sometimes  show 
marked  fatty  change  anatomically  without  corresponding  increase  chemically. 

4  Pieces  of  tissue  implanted  into  animals  may  show  a  peripheral  fatty  meta- 
morphosis or  infiltration,  yet  show  upon  analysis  a  decreased  fat  content 
(Dietrich,  Verh.  Deut.  Path.  Gesellsch.,  1905  (9),  212). 


CAUSES  OF  FATTY  METAMORPHOSIS  339 

Lecithin  and  Other  Intracellular  Lipoids.— It  has  often  been  sug- 
gested that  the  lecithin  of  the  cell  might  act  as  a  source  of  the  fat  in 
fatty  degeneration,  but  it  has  been  quite  conclusively  shown  that  this  is 
not  the  case,  numerous  investigators  having  found  that  the  amount  of 
lecithin  remains  nearly  normal  in  cells  even  during  the  most  extreme 
fatty  degeneration.1  The  lecithin  may  be,  and  undoubtedly  is,  one  of 
the  fatty  substances  that  become  visible  during  cell  autolysis,  and  pre- 
sumably other  lipoids  also  appear. 

Kaiserling  and  Orgler 2  have  described  under  the  non-committal  name 
of  "myelin''  certain  intracellular  droplets  that  may  be  found  in  the 
cortical  cells  of  the  normal  adrenal,  in  amyloid  kidneys,  pneumonic  exu- 
dates,  tumor  cells,  retrogressive  thymus  tissue,  corpus  luteum,  and  bron- 
chial secretions ;  and  which  differ  from  fat  in  being  doubly  refractile 
and  in  staining  but  faintly  gray  with  osmic  acid,  although  taking  up  fat 
stains  well.  Their  average  size  is  4-6  microns,  and  they  dissolve  in  ether 
and  chloroform  readily,  but  poorly  in  alcohol.  Probably  this  myelin  is 
one  of  the  cell  lipoids,  possibly  "  protagon  "  made  visible  by  cell  degen- 
eration, for  except  in  the  adrenal  the  cells  containing  it  are  in  a  necro- 
biotic  state.  This  is  supported  by  Albrecht's  observation  that  post- 
mortem myelin  formation  is  checked  by  heating  the  cells  to  58° -62°,  a 
temperature  which  destroys  the  autolytic  enzymes.3 

Summary. — We  must  conclude,  therefore,  that  fatty  de- 
generation of  an  organ  means,  in  the  case  of  the  liver,  myocar- 
dium, and  pancreas  an  infiltration  of  fat  from  outside  into  cells 
which  have  been  degenerated  by  the  action  of  poisons  or  other 
injurious  influences.  In  the  kidney,  spleen,  and  muscles  an 
increase  of  fat  seldom  occurs  from  these  causes,  but  the  cells 
may  show  a  marked  fatty  metamorphosis  through  the  setting 
free  of  the  invisible  intracellular  fat  by  autolytic  changes. 

CAUSES  OF  FATTY  METAMORPHOSIS 

Nevertheless,  the  old  anatomical  distinction  of  infiltration 
and  degeneration  still  remains,  provided  we  do  not  hold  to  the 
original  idea  that  the  term  degeneration  implies  that  the  cell 
proteid  has  been  converted  into  fat ;  for  we  must  recognize  that 
under  some  conditions  the  cells  may  take  up  great  quantities  of 
fat  without  suffering  any  appreciable  degenerative  changes, 
whereas  in  other  instances  the  appearance  of  fat  is  associated 

lLusena,  Lo  Sperim.,  1903  (57),  29;  Kubow,  Dissert.,  Kopenhagen,  1903; 
Rubow,  Arch.  f.  exp.  Pathol.,  1905  (52),  173.  Waldvogel,  however,  maintains 
that  in  fatty  degeneration  and  in  autolysis  there  occurs  a  decrease  in  the  lecithin, 
associated  with  an  increase  in  "  jecorin,"  "  protagon,"  fatty  acids,  neutral  fats, 
and  cholesterin.  There  is  so  much  doubt  concerning  the  chemical  status  of 
"jecorin"  and  "protagon"  that  these  statements  are  in  need  of  much  con- 
firmation. (See  Waldvogel  and  Mette,  Munch,  med.  Woch.,  1906  (53),  402, 
for  review  of  Waldvogel's  work.) 

2  Virchow's  Arch.,  1902  (167),  296. 

3  Cent.  f.  Path.,  1904  (15),  982.     See  also  Orgler,  Virchow's  Arch.,  1904 
(176),  413;  and  Albrecht,  Verh.  Deut.  Path.  Gesellsch.,  1903  (6),  95. 


340  RETROGRESSIVE  PROCESSES 

with  marked  and  complete  disintegration  of  both  nucleus  and 
cytoplasm.  Furthermore,  we  have  yet  to  explain  why,  under 
some  conditions,  the  fat  is  removed  from  the  fat  depots  to  be 
stored  up  in  the  liver  or  other  organs.  By  applying  the  facts 
recently  brought  out  concerning  fat  metabolism,  particularly  by 
Kastle  and  Loevenhart,1  a  satisfactory  explanation  seems  to  be 
possible.  Fat  is  always  utilized  and  transported  in  the  form 
of  its  two  constituents,  fatty  acid  (or  soaps)  and  glycerin,  which 
are  diffusible  and  soluble.  It  enters  and  leaves  the  cells  in  this 
condition,  being  split  or  combined,  as  may  be  necessary  to  pro- 
duce equilibrium,  by  the  action  of  lipase,  which  is  present 
within  the  cells  and  in  the  blood  and  lymph.  Under  normal 
conditions  there  is  little  free  visible  fat  in  the  cells  of  the  paren- 
chymatous  organs,  because  it  is  largely  used  up  through  oxida- 
tion of  the  glycerin  and  fatty  acids  by  the  action  of  the  intra- 
cellular  oxidases.  Where  there  is  abundant  lipase  and  but 
little  oxidative  activity,  as  is  the  case  in  the  areolar  fat  tissue, 
fat  accumulates  in  large  amounts.  When,  for  any  reason,  the 
oxidative  power  of  the  parenchymatous  organs  is  reduced,  fat 
accumulates  in  them  as  it  does  in  the  fat  depots  normally,  and 
we  have  an  excess  of  fat  in  the  parenchymatous  cells ;  thus,  in 
pulmonary  tuberculosis,  severe  or  protracted  anemias,  etc.,  a 
great  accumulation  of  fat  occurs,  particularly  in  the  liver,  where 
normally  active  oxidative  processes  continually  balance  the 
action  of  the  abundant  lipase  of  the  liver-cells. 

If  the  fat  accumulates  in  cells  that  are  structurally  normal  or 
nearly  so,  the  fat-droplets  fuse  together  under  the  pressure  of 
the  cytoplasm,  and  we  get  tne  picture  of  a  typical  fatty  in- 
filtration. If  the  cells  are  much  disintegrated  through  the 
action  of  the  poison, — e.  g.,  phosphorus,  bacterial  toxins,  etc., — 
the  accumulating  fat-droplets  are  not  crowded  into  one  large 
droplet,  but  lie  free  in  the  granular  debris  of  the  disintegrating 
cell,  constituting  the  typical  appearance  of  fatty  degeneration. 
Fatty  degeneration  is  usually  brought  about  by  poisons,  while 
fatty  infiltration  depends  usually  upon  decreased  oxidation,  due 
to  lack  of  either  oxygen  or  hemoglobin  in  the  blood.  If  the 
anemia  is  extreme,  however,  the  cells  degenerate,  and  then  we 
find  a  true  fatty  degeneration  caused  by  lack  of  oxygen.  Thus, 
in  an  anemic  infarct  fat  accumulates  about  the  periphery  of  the 
dead  area,2  probably  because  fatty  acids  and  glycerin  diffuse  in 
slowly  from  the  surrounding  parts  where  circulation  still  goes 
on,  and  are  built  up  into  fat  by  the  cell  lipase,  for  in  anemic 

1  See  consideration  of  this  topic  on  page  67, 

2  Fischler,  Cent.  f.  Path.,  1902  (13),  417. 


CAUSES  OF  FATTY  METAMORPHOSIS  341 

areas  the  intracellular  oxidases  cannot  destroy  these  substances 
as  they  normally  do,  because  of  lack  of  oxygen.  The  accumu- 
lation of  fat  in  dead  areas  depends,  therefore,  on  the  fact  that 
the  constituents  of  fat  can  diffuse  into  the  dead  tissue,  whereas 
the  oxygen,  being  held  in  the  corpuscles,  cannot  enter  the 
anemic  area. 

It  is  to  be  supposed  that  poisons  also  cause  fatty  degenera- 
tion in  a  similar  way — by  interfering  with  oxidation.  We  have 
much  evidence  that  in  phosphorus,  chloroform,  and  other  poison- 
ing associated  with  fatty  degeneration  of  the  liver,  oxidation  is 
impaired.1  If  we  imagine  for  a  moment,  a  cell  in  which  oxida- 
tion is  checked  by  any  means,  we  shall  have  in  this  cell  the 
lipase  and  the  proteolytic  enzymes  not  balanced,  as  they  nor- 
mally are  by  the  action  of  the  oxidases,  and  hence  the  processes 
of  cell  autolysis  and  of  the  accumulation  of  fat  by  the  lipase 
will  go  on  uncontrolled.  The  result  will  be  a  disintegrated 
cell  containing  many  fat-droplets,  i.  e.,  fatty  degeneration.2 

Summary. — Fatty  metamorphosis  involves  changes  of  two 
kinds.  First,  infiltration  of  fat,  which  occurs  when  the  oxi- 
dative  power  of  the  cells  is  decreased,  so  that  fat  is  not  des- 
troyed, but  is  accumulated  from  the  blood  under  the  influence 
of  the  lipase  of  the  cells ;  if  there  is  not  any  serious  injury  to 
the  cells,  the  histological  changes  consist  in  the  accumulation  of 
one  or  a  few  large  droplets  of  fat  in  each  cell,  constituting  the 
condition  kno^yll  anatomically  as  "fatty  infiltration."  This 
occurs,  pathologically,  chiefly  in  the  liver.  If  at  the  same 
time  the  cytoplasm  is  disintegrated  through  autolytic  changes, 
the  fat-droplets  do  not  fuse,  but  remain  as  small,  more  or  less 
discrete,  fat  granules  among  the  granules  of  cell  debris,  consti- 
tuting the  microscopic  picture  of  "  fatty  degeneration " ;  this 
condition  occurs  particularly  in  the  heart  and  liver. 

Second,  each  cell  contains  a  large  amount  of  fat  (5-25  per 
cent,  of  its  dry  weight),  which  is  so  combined  that  it  cannot  be 
detected  microscopically  ;  this  fat  may  be  liberated  during  the 
autolytic  processes  of  cell  disintegration  and  become  visible, 

1  See  Welsch,  Arch.  int.  de  pharm.  et  therap.,  1905  (14),  211. 

2  Interference  with  oxidation  does  not  necessarily  imply  destruction  of  the 
oxidases.     As  yet  we  know  practically  nothing  concerning  the  oxidases  of  the 
cells  in  disease,  and  the  above  hypothesis  has  yet  to  be  demonstrated.     Duc- 
cheschi  and  Almagia  (Arch.  Ital.  Biol.,  1903  (39), 29)  found  the  normal  amount 
of  lipase  in  phosphorus-livers,  but  also  observed  no  decrease  in  ability  to  oxi- 
dize salicylic  aldehyde,  which,  however,  does  not  prove  a  normal  power  to 
oxidize  fats.    Gierke's  observation  (Ziegler's  Beitr.,  1905  (37),  502)  that  glyco- 
gen  and  fat  accumulate  under  identical  conditions  might  be  cited  as  indicating 
decreased  oxidative  power,  were  it  not  in  direct  contradiction  to  the  results 
obtained  by  Kosenfeld. 


342  RETROGRESSIVE  PROCESSES 

constituting  a  macroscopical  and  microscopical  degeneration,  but 
without  any  actual  increase  in  fat — this  condition  occurs  particu- 
larly in  the  kidney  and  nervous  system.  Third,  a  combination 
of  both  of  the  above  processes,  infiltration  of  fat  and  liberation  of 
masked  intracellular  fat,  may  occur  simultaneously  in  an  organ.1 

PROCESSES  RELATED  TO  FATTY  METAMORPHOSIS 
ADIPOCERE 

This  apparent  transformation  of  the  substance  of  dead  bodies 
into  a  wax-like  material  was  for  a  long  time  looked  upon  as 
evidence  of  a  transformation  of  proteid  into  fat,  but  in  the 
light  of  more  recent  investigations  this  view  can  hardly  be  held. 
Adipocere  is  the  product  of  a  process  that  occurs  particularly  in 
bodies  buried  in  very  wet  places  or  lying  in  water,  and  results 
in  an  apparent  replacement  of  the  muscles  and  other  soft  parts 
(but  not  the  glandular  organs)  by  a  mass  consisting  of  a  mix- 
ture of  fatty  acids  in  crystalline  and  amorphous  form,  and 
soaps,  particularly  ammonium,  magnesium,  and  calcium  salts 
of  palmitic  and  stearic  acid  (the  oleic  acid  largely  disappearing 
during  the  process).  The  resulting  material  is  absolutely  resis- 
tant to  putrefaction,  and  hence  remains  intact  for  many  years. 
This  replacement  of  the  soft  parts  is,  however,  only  apparent, 
for  the  total  weight  of  a  body  in  this  condition  is  much  lighter 
than  that  of  the  original  body ;  indeed,  one  is  always  surprised 
at  the  light  weight  on  lifting  such  a  specimen.  Adipocere 
occurs  almost  exclusively  in  fat  bodies,  and  it  seems  probable  that 
all  the  soaps  and  fatty  acids  found  are  farmed  from  the  original 
fats  of  the  corpse.  These  gradually  flow  into  the  places  left  by 
the  disintegrating  muscle,  etc.,  a  process  that  occurs  readily  in 
cadavers,  according  to  Zillner  ;2  or  the  infiltration  may  be  accom- 
plished through  diffusion  of  the  ammonium  soaps  formed 
during  the  decomposition.  As  the  subcutaneous  fat  is  hardened 
by  the  formation  of  soaps,  and  the  bones  remain  to  hold  the  parts 
in  position,  the  general  form  of  the  body  is  preserved,  creating 
the  impression  that  its  entire  substance  has  been  converted  into 
adipocere,  when  the  total  mass  may  actually  weigh  but  twenty 

1  The  above  conception  of  the  processes  involved  in  fatty  metamorphosis 
has  been  held  by  the  writer  for  several  years,  and  is  more  fully  discussed  in 
other  publications  (Jour.  Amer.  Med.  Assoc.,  1902  (38),  220;    ibid..,    1906 
(46),  341).     Ribbert  (Deut.  med.  Woch.,  1903  (29),  793)  has  also  advanced  a 
similar  explanation  for  the  morphological  differences  between  fatty  "  degenera- 
tion "  and  "  infiltration,"  i.  «.,  that  the  degenerative  changes  are  independent 
of  the  fatty  accumulation. 

2  Vierteljahrsch.  f.  gericht.  Med.,  1885  (42),  1. 


ADIPOCERE  343 

pounds  or  so,  and,  according  to  Zillner's  estimate,  not  more  than 
one-tenth  of  the  muscle  substance  is  replaced  by  adipocere. 
This  false  impression  is  probably  responsible  for  much  of  the 
mistaken  idea  concerning  the  conversion  of  muscle  proteids  into 
fatty  acids. 

Numerous  attempts  have  been  made  to  prove  that  muscle 
could  be  thus  converted  into  fatty  acids  and  soaps,  but  although 
success  has  been  claimed  by  a  few,  the  results  are  not  entirely 
convincing.1  Bacteria  can  convert  proteids  into  fats,  beyond 
a  doubt,  and  they  may  do  so  to  some  slight  extent  in  adipocere 
formation,  but  probably  this  factor  is  not  important. 

In  the  light  of  our  present  conception  of  fat  metabolism  it  is 
probable  that  the  process  of  adipocere  formation  occurs  as 
follows  :  The  fatty  acids  of  the  fat  tissue  are  combined  by  the 
ammonia  formed  during  putrefaction,  removing  these  fatty  acids 
from  the  normal  balance  of  fat  and  fatty  acids  in  the  fat  tissue ; 
as  a  result,  the  lipase  of  the  fat  tissue  continues  to  split  up  the 
fat,  and  more  fatty  acids  are  produced,  which  likewise  go  to 
form  soaps.  This  continues  until  practically  all  the  neutral 
fat  has  been  decomposed,  the  glycerin  diffusing  rapidly  away. 
The  soluble  soaps,  which  the  bacteria  do  not  attack,  diffuse 
into  the  softened  muscle  tissue,  which  they  gradually  replace  in 
part.  In  the  meantime,  from  the  more  soluble  ammonium  soaps, 
calcium  and  magnesium  soaps  are  being  slowly  formed,  accord- 
ing to  the  usual  rule  of  double  decomposition  (that  the  least 
soluble  salt  will  be  formed  under  such  conditions).  The  oleic 
acid  seems  to  be  converted  into  the  higher  fatty  acids  (Sal- 
kowski).2  It  is  also  possible  that  the  saponification  is  due  to 
the  gradual  action  of  the  alkaline  fluids  produced  in  decomposi- 
tion of  the  tissues,  or  to  the  alkalinity  of  the  water  in  which 
the  body  lies.  Possibly  bacteria  may  be  responsible  for  this 
decomposition  of  the  fats  rather  than  the  body  lipase,  for 
Eijkman 3  has  observed  that  certain  bacteria  growing  in  fat-con- 
taining agar  produce  calcium,  ammonium,  and  sodium  soaps, 
simulating  adipocere. 

Zillner 4  gives  the  following  scheme  of  the  changes  that  take 
place  in  a  cadaver  undergoing  adipocere  formation  :  (1)  Migra- 
tion of  fluid  contents  of  the  body  (imbibition  of  blood  and 
transudation) — one  to  four  weeks.  (2)  Decomposition  of  super- 
ficial epidermis,  then  of  corium — first  two  months.  (3)  Decom- 
position of  muscle  and  gland  parenchyma,  until  only  the 

^ee  Eosenfeld,  Ergeb.  der.  Physiol.,  Abt.  1,  1902  (1),  659. 

2  Festschr.  f.  Virchow,  1891,  p.  23. 

3  Cent.  f.  Bakt,  1901  (29),  847.  *  Loc.  cit. 


344  RETROGRESSIVE  PROCESSES 

inorganic  part  of  the  bones  and  the  connective  and  elastic  tis- 
sues remain — three  to  twelve  months.  (4)  Migration  of  neutral 
fat,  crystallization  and  partial  saponification  of  the  higher  fatty 
acids  in  the  panniculus ;  transformation  of  the  blood  pigment 
into  crystalline  form — four  to  twelve  or  more  months. 

LIPEMIA 

Normally  the  blood  contains  a  considerable  amount  of  fat, 
varying  somewhat,  but  not  greatly,  with  the  diet.  Engelhardt L 
found  in  eight  healthy  persons  an  average  of  0.194  per  cent., 
with  a  maximum  of  0.237  per  cent.,  and  a  minimum  of  0.101 
per  cent. ;  in  five  cachectic  patients  the  quantities  were  quite 
the  same.  Rumpf,2  in  a  large  number  of  morbid  conditions,  how- 
ever, found  the  solid  substance  of  the  blood  to  contain  an  aver- 
age of  0.452  per  cent,  of  fat,  but  with  variations  between  0.035 
per  cent,  and  2.20  per  cent.  It  is,  therefore,  extremely  diffi- 
cult to  say  just  when  the  amount  of  fat  in  the  blood  is  large 
enough  to  be  considered  as  a  lipemia.  B.  Fischer 3  states  that 
we  may  speak  of  a  pathological  lipemia  when  we  have  a  distinctly 
cloudy  blood  or  serum,  which  is  clarified  by  shaking  with  ether, 
through  the  dissolving  out  of  fat  which  can  then  be  separated 
from  the  ether.  Earlier  writers  described,  incorrectly,  lipemia 
in  many  conditions,  but  recent  writers  mention  it  chiefly  as 
occurring  in  alcoholism  and  diabetes.  By  far  the  greatest  amounts 
of  fat  are  observed  in  the  latter  condition.  Neisser  and  Der- 
lin4  found  19.7  per  cent,  of  fat  in  the  blood  of  a  patient  with 
diabetic  coma  (after  death  24.4  per  cent,  was  found)  whose 
urine  contained  0.8  per  cent,  of  fat,  and  through  analysis  of  this 
and  other  material  came  to  the  conclusion  that  the  fat  comes 
directly  from  the  chyle ;  i.  e.,  that  it  is  food  fat,  not  body  fat. 
Fischer  found  an  average  of  18.129  per  cent,  in  his  case,  includ- 
ing at  least  0.478  per  cent,  of  cholesterin,  with  no  lipuria  and 
very  small  amounts  of  fatty  acids  ;  of  the  fat,  about  67.5  per 
cent,  was  olein. 

It  is  an  important  question  whether,  with  such  high  quanti- 
ties of  fat  in  the  blood,  fat  embolism  may  result,  for  it  is  pos- 
sible that  at  least  some  of  the  cases  of  diabetic  coma  are  due  to 
such  fat  embolism  in  the  cerebral  vessels.  Ebstein 5  considers 
this  a  possible,  but  not  a  common,  occurrence,  because  the  drop- 
lets are  too  small  to  cause  occlusion  of  the  vessels  unless  they 

1  Deut.  Arch.klin.  Med.,  1901  (70),  182. 

2  Virchow's  Arch.,  1903  (174),  163. 

3  Virchow's  Arch.,  1903  (172),  30.  Kesume'  and  complete  literature. 
4Zeit.  klin.  Med.,  1904  (51),  428. 

5  Virchow's  Arch.,  1899  (155),  571. 


PATHOLOGICAL   OCCURRENCE  OF  FATTY  ACIDS     345 

combine  to  form  large  droplets.  Fischer  doubts  if  the  droplets 
ever  fuse  together  enough  to  cause  embolism,  supporting  his 
contention  both  by  experiments  and  clinical  records. 

The  cause  of  lipemia  has  not  yet  been  satisfactorily  deter- 
mined. In  alcoholism  it  is  commonly  ascribed  to  a  failure  to 
burn  fat,  because  of  the  presence  of  the  more  readily  oxidized 
alcohol,  and  the  common  coexistence  of  diabetes  and  lipemia  sug- 
gests for  both  a  common  cause ;  i.  e.y  lack  of  oxidation  of  fat  and 
sugar.  In  corroboration  may  be  cited  the  occurrence  of  lipemia 
in  other  conditions  associated  with  defective  oxidation  ;  i.  e., 
pneumonia,  anemia,  phosphorus-poisoning.  As  we  are  still 
unfamiliar  with  the  essential  factors  and  steps  in  the  oxidation 
of  fat,  it  would  be  mere  speculation  to  attempt  to  explain  further 
the  reason  for  the  failure  of  destruction  of  the  fat.  The  origin 
of  the  fat  in  lipemia  is  likewise  undetermined.  Ebstein  con- 
siders that  it  arises  partly  from  the  food,  partly  from  fatty 
degeneration  of  the  cells  of  the  blood,  the  vessel-walls,  and  the 
viscera.  Neisser  and  Derlin  consider  it  as  merely  food  fat 
coming  from  the  chyle  and  accumulated  in  the  blood.  Fischer 
believes  that  it  is  largely  derived  from  the  fat  depots,  and  that 
because  of  loss  of  the  lipolytic  power  of  the  blood  it  cannot  be 
rendered  diffusible,  and  hence  it  cannot  enter  the  tissues  where 
it  is  normally  consumed. 

PATHOLOGICAL  OCCURRENCE  OF  FATTY  ACIDS 

Fatty  acids  occasionally  occur  free  in  pathological  processes. 
The  best  example  of  this  is  fat  necrosis  (q.  v.\  where  crystals  of 
fatty  acids  appear  in  the  necrotic  fat-cells,  arising  through 
splitting  of  fat,  and  later  becoming  combined  with  calcium  from 
the  blood.  Similar  crystals,  consisting  of  a  mixture  of  pal- 
mitic and  stearic  acids,  frequently  called  margarin  or  margaric 
add  crystals,  may  be  found  in  decomposed  pus,  in  sputum  from 
bronchiectatic  cavities,  and  from  gangrene  of  the  lungs,  in  gan- 
grenous tissue,  and  in  atheromatous  areas.  According  to 
Schwartz  and  Kayser,1  the  free  fatty  acids,  at  least  in  pulmonary 
gangrene,  arise  from  lipolysis  by  bacterial  action  rather  than  by 
the  lipase  of  the  tissues.  Eichhorst  found  crystals  of  fatty 
acids  in  the  neighborhood  of  acute  patches  of  sclerosis  in  the 
central  nervous  system  in  multiple  sclerosis,  and  McCarthy 2 
found  them  in  a  spinal  cord  undergoing  secondary  degeneration 
from  compression. 

1  Zeit.  klin.  Med.,  1905  (56),  111. 

2  Univ.  of  Penn.  Med.  Bull.,  1903  (16),  141. 


346  RETROGRESSIVE  PROCESSES 

The  fatty  acids  may  be  stained  green  by  copper  acetate,  ac- 
cording to  Benda's  method,  and  if  then  treated  with  hematox- 
ylin,  they  turn  black.1  Fischler  and  Gross2  state  that  fatty 
acids  are  present  in  atheromatous  areas  and  about  the  margin 
of  anemic  infarcts,  but  are  not  recognizable  by  this  method  in 
such  fatty  degenerations  as  pneumonic  exudates,  caseation,  etc. 
Klotz 3  considers  that  calcium  soaps  are  formed  as  the  first  step 
in  pathological  calcification,  according  to  microchemical  evi- 
dence ;  but  a  chemical  investigation  of  the  same  question  did 
not  give  the  writer  positive  results.4 

PATHOLOGICAL  OCCURRENCE  OF  CHOLESTERIN  5 

Cholesterin  in  crystals  is  found  under  somewhat  the  same  con- 
ditions as  the  fatty  acids,  and  although  cholesterin  is  not  a  fat,  but 
an  alcohol,  its  physical  properties  are  so  similar  that  it  may  be  con- 
sidered in  this  place.  (See  "  Gall-stones,"  Chap,  xv,  for  further 
discussion.)  The  characteristic  large  flat  plates  of  cholesterin 
may  be  found  in  any  tissue  in  which  cells  are  undergoing  slow 
destruction,  and  where  absorption  is  poor.  Therefore,  they  are 
found  frequently  in  atheromatous  patches  in  the  blood-vessels, 
encapsulated  caseous  areas,  old  infarcts  and  hematomas,  inspis- 
sated pus-collections,  dermoid  cysts,  hydrocele  fluids,  etc.; 
especially  large  amounts  occur  in  the  cholesteatomatous  tumors 
of  the  ear  and  cranial  cavity.6  In  liquids  the  crystals  form 
glistening  scales ;  in  fresh  tissues  they  may  be  recognized  by 
their  solubility  in  ether,  chloroform,  hot  alcohol,  etc.,  and  by 
their  color  reactions.  In  histological  specimens  prepared  by  the 
usual  methods  the  cholesterin  is  dissolved  out,  but  the  resulting 
clear-cut  clefts  are  quite  characteristic.  In  fresh  specimens 
in  which  cholesterin  crystals  are  present,  on  treatment  with  five 
parts  concentrated  sulphuric  acid  and  one  of  water,  the  edges 
of  the  crystals  become  carmine  red,  then  violet.  Concentrated 
sulphuric  acid  plus  a  trace  of  iodin  colors  the  crystals  in  se- 
quence, violet,  blue,  green,  and  red.  Hirschsohn  7  recommends 
a  reaction  with  a  90  per  cent,  solution  of  trichloracetic  acid  in 
HC1,  which  gives  red,  then  violet,  then  blue. 

Since  all,  or  nearly  all,  cells  contain  cholesterin,  it  is  perhaps 
accumulated  as  one  of  the  least  soluble  products  of  their 

1  Fischler,  Cent.  f.  Path.,  1904  (15),  913. 
^ieglei-'s  Beitr.,  1905  (7th  suppl.),  343. 

3  Jour.  Exp.  Med.,  1905  (7),  633. 

4  Wells,  Jour.  Med.  Research,  1906  (14),  491.  ^ 

5  Concerning  the  chemistry  of  cholesterin  see  introductory  chapter. 

6  See  Bostroem,  Cent.  f.  Path.,  1897  (8),  1. 

7  Pharm.  Centralhalle,  1902  (43),  357. 


AMYLOID  347 

disintegration.  The  origin  of  the  normal  cell  cholesterin  is 
unknown.  According  to  Stadelmann,1  that  which  enters  with  the 
food  is  not  absorbed,  hence  the  considerable  amounts  that  are 
constantly  being  thrown  out  by  the  bile  and  the  sebaceous 
glands  must  be  replaced  by  cellular  activity.  Cholesterin  is 
generally  considered,  but  without  convincing  proof,  to  be  a 
product  of  proteid  decomposition ;  if  this  is  true,  then  the 
cholesterin  found  in  disintegrating  tissues  may  be  formed  from 
the  cell  proteids  during  their  decomposition.2  Apparently 
cholesterin  crystals  may  be  slowly  removed,  the  chief  factor 
probably  being  the  giant-cells  that  are  often  found  surrounding 
them.3  In  general  they  behave  as  inert  foreign  bodies. 

AMYLOID4 

Virchow,  in  1853,  made  the  first  study  of  the  nature  of  the 
substance  characteristic  of  "  lardaceous "  degeneration,  and 
considered  it  to  be  a  sort  of  animal  cellulose,  because  it  often 
became  blue  if  treated  with  iodin  followed  by  sulphuric  acid. 
To  this  resemblance  in  staining  reaction  we  owe  the  unfortunate, 
misleading,  but  generally  used,  name  amyloid.5  It  was  but  a 
few  years  (1859)  before  Friedreich  and  Kekule*  showed  that 
the  substance  in  question  was  of  proteid  nature ;  their  methods 
were  very  crude,  but  the  main  fact  was  soon  better  substan- 
tiated by  Kiihne  and  RudnefF  (1865).  Krawkow,6  however, 
in  1897  gave  us  the  first  good  idea  of  the  composition  of  amy- 
loid substance  through  his  amplification  of  Oddi's 7  observation 
that  amyloid  organs  contain  chondroitin-sulphuric  acid,  finding 
that  amyloid  is  a  compound  of  proteid  with  this  acid,  similar  to 
nucleoproteid,  which  is  a  compound  of  nucleic  acid  and  proteid. 

1  Dissert.,  Freiburg  in  der  Schweiz,  1 898. 

2  Of  historical  interest  is  Austin  Flint's  idea  that  cholesterin  in  the  blood 
is  an  important  factor   in  intoxications,   especially  in  icterus  (Amer.  Jour. 
Med.  Sci.,  1862  (44),  29).     All  recent  evidence  is  to  the  effect  that  cholesterin 
is  not  toxic. 

3  See  LeCount,  Jour.  Med.  Research,  1902  (7),  166. 

*  General  literature  to  1893,  see  Wichmann,  Ziegler's  Beitr.,  1893  (13),  487 ; 
also  Lubarsch,  Ergeb.  allg.  Path.,  1897  (4),  449 ;  modern  ideas  are  summed  up 
in  a  discussion  in  the  Verb.  Deut.  Path.  Gesellsch.,  1904  (7),  2-51. 

5  In  view  of  the  fact  that  this  substance  is  chemically  related  to  chondrin, 
and  that  it  also  closely  resembles  this  substance  physically,  it  has  seemed  to 
the  writer  that  the  name  "chondroid"  would  be  much  more  appropriate  than 
any  of  the  many  more  or  less  misleading  and  inappropriate  titles  that  are  at 
present  in  use.     The  very  multiplicity  of  these  terms,  however,  prohibits  any 
attempt  to  introduce  still  another.     A  particularly  unfortunate  source  of  con- 
fusion exists  in  the  use  of  the  name  amyloid  for  a  vegetable  substance,  formed 
by  the  action  of  acids  upon  cellulose. 

6  Arch.  exp.  Path.  u.  Pharm.,  1897  (40),  196. 

7  Ibid.,  1894  (33),  377. 


348 


RETROGRESSIVE  PROCESSES 


Chondroitin-sulphuric  acid,  which  has  been  studied  especially  by 
Morner  and  by  Schmiedeberg, l  has  the  formula  C18H27NSO17,  according 
to  the  latter,  and  yields  on  cleavage  chondroitin  and  sulphuric  acid,  as 
follows : 

C18H27NS017  +  H20  ==  C18H27N014  +  H2SO4. 

(chondroitin) 

Chondroitin  is  a  gummy  substance  which  in  turn  may  be  split  into  acetic 
acid  and  a  reducing  substance,  chondrosin.  Chondroitin-sulphuric  acid 
is  the  characteristic  component  of  cartilage,  but  it  is  also  found  in  mucin 
(Levene),  and  in  the  walls  of  the  aorta  and  other  elastic  structures 
(Krawkow).  It  has  also  been  found  in  a  uterine  fibroma  and  in  bone 
tissue  by  Krawkow,  but  could  not  be  found  in  the  parenchymatous 
organs,  normal  and  pathological,  or  in  chitinous  structures.  Morner 
has  also  found  it  in  a  chondroma. 

Chemistry  of  Amyloid. — Krawkow  separated  amyloid 
from  nucleoproteid,  to  which  it  is  most  closely  related,  by  dis- 
solving both  substances  from  the  minced  amyloid  organs  with 
ammonia,  precipitating  with  acid,  and  then  taking  up  the  amyloid 
with  Ba(OH)2  solution,  in  which  the  nucleoproteid  does  not  dis- 
solve. Amyloid  thus  isolated  is  a  nearly  white  powder,  which 
is  easily  soluble  in  alkalies,  but  slightly  in  acids,  and  is  very 
resistant  to  pepsin  digestion.  The  elementary  composition  was 
found  by  Krawkow  to  be  approximately  as  follows  : 

C  =  49-50$;  H  =  6.65-7$;  N=  13.8-14$;  8  =  2.65-2.9$;  P  in  traces  only. 

Quite  similar  analytic  results  have  been  obtained  by  Neu- 
berg,2  who  corroborated  Krawkow's  finding  of  a  body  of  ap- 
parently similar  composition  in  the  normal  aorta.  Neuberg  has 
studied  especially  the  proteid  constituent  of  the  amyloid  com- 
pound, and  found  it  characterized  by  a  high  proportion  of  diam- 
ino-nitrogen,  as  compared  with  most  proteids,  as  shown  in  the 
following  table  giving  the  percentage  of  the  total  N  contained  in 
each  of  the  three  forms,  amid-nitrogen  (ammonia),  monamino- 
acids,  and  diamino-acids  : 

TABLE  I. 


Monamino- 
acid 
nitrogen. 

Diamino- 
acid 
nitrogen. 

Amid 
nitrogen. 

Liver  amyloid 

43.2 

51.2 

4.9 

Spleen  amyloid 

30.6 

57.0 

11.2 

Aorta  "  amyloid  "                        

54.9 

36.0 

8.8 

Gelatin 

625 

35.8 

1.6 

Casein    . 

76.0 

11.1 

13.4 

1 . Morner,  Skand.  Arch.  Physiol.,  1889  (1),  210;  Zeit.  physiol.  Chem.,  1895 
(20),  357,  and  1897  (23),  311 ;  Schmiedeberg,  Arch.  exp.  Path.  u.  Pharm., 
1891  (28),  358. 

2  Verb.  Dent.  Path.  Gesell.,  1904  (7),  19. 


AMYLOID 


349 


The  variations  in  the  composition  of  the  different  amyloids, 
as  shown  in  the  above  table,  indicate  that  the  proteid  group 
may  vary  in  different  organs  or  in  different  cases,  and  also 
indicate  that  the  "  amyloid-like  "  substance  of  normal  vessels  is 
not  the  same  as  the  pathological  substance.  Corresponding 
variations  were  found  in  the  apportionment  of  the  sulphur 
between  that  which  is  in  the  form  of  oxidized  sulphur  and  the 
unoxidized  sulphur.  The  proportion  of  the  different  amino- 
acids  in  the  proteid  constituent  of  amyloid  is  strikingly  like 
that  of  thymus  histon,  and  entirely  dissimilar  to  the  apparently 
closely  related  elastin,  as  shown  by  the  following  table : 

TABLE  II. 


Cleavage  products  (in  percentages). 

Amyloid. 

Elastin. 

Thymus 
histon. 

Grlycocoll                    •               

0.8 
22.2 
3.8 
4.0 
3.1 
13.9 
11.6 

25.8 
45.0 
0.7 
0.3 
1.7 
0.3 

0.5 
11.8 
3.7 
5.2 
1.5 
14.5 
7.7 

Leucin                      ....                

This  carries  out  the  resemblance  of  amyloid  to  nucleoproteids, 
and,  likewise,  Neuberg  found  amyloid  very  slowly  digested  by 
pepsin,  and  much  better  by  trypsin,  although  less  rapidly  than 
simple  proteid ;  it  is  also  destroyed  by  autolytic  enzymes,  for 
amyloid  tissues  readily  undergo  autolysis.  Neuberg  considers, 
from  the  above  results,  that  amyloid  is  probably  a  transforma- 
tion-product of  the  tissue  proteid,  similar  to  the  transformation 
of  simple  proteids  into  protamins  that  occurs  in  the  testicle 
of  spawning  salmon  as  they  go  up  the  streams,  as  shown  by 
Miescher's  classical  studies. 

Krawkow  considers  that  amyloid  differs  from  normal  chon- 
droitin-sulphuric  acid  compounds,  such  as  cartilage,  in  that  in  the 
latter  the  acid  radical  is  in  a  loose  combination  with  the  proteid, 
while  in  amyloid  the  combination  is  a  very  firm  one,  perhaps  in  the 
nature  of  an  ester.  The  occurrence  of  the  typical  amyloid  reac- 
tion in  what  appears  otherwise  to  be  normal  cartilage,  occasion- 
ally observed  in  senile  tissues,  may  be  due  to  the  transformation 
of  loosely  bound  into  firmly  bound  chondroitin-sulphuric  acid. 
In  any  event,  amyloid  is  not  essentially  a  pathological  product, 


350  RETEOGEESSIVE  PROCESSES 

but  rather  a  slightly  modified  normal  constituent  of  the 
body. 

Staining  Properties. — The  classical  reaction  for  amyloid 
is  its  staining  a  reddish  brown  when  treated  with  iodin  (best  as 
LugoPs  solution)  in  the  fresh  state.  Such  stained  specimens, 
if  afterward  treated  with  dilute  sulphuric  acid,  usually  become 
blue  or  greenish,  but  may  merely  turn  a  deeper  brown.  Occa- 
sionally old  compact  amyloid  may  stain  bluish  or  green  with 
iodin  alone.  The  iodin  reaction  disappears  in  specimens  that 
have  been  kept  for  some  time  in  preserving  fluids,  or  in  tissues 
that  have  become  alkaline,  and  is  generally  less  persistent  than 
the  metachromatic  staining  by  methyl-violet  or  methyl-green, 
which  color  the  amyloid  red.  Occasionally  an  otherwise  typical 
amyloid  will  fail  to  react  to  iodin,  but  will  stain  well  with 
methyl- violet.  All  these  variations  may  occur  in  different 
specimens  from  the  same  body,  and  the  blue  iodin-sulphuric 
acid  reaction  is  usually  given  well  only  by  splenic  amyloid. 
These  variations  probably  depend  upon  the  age  and  stage  of 
development  of  the  amyloid,  or  upon  secondary  alterations,  and 
are  perhaps  related  to  Neuberg's  observations  on  the  difference 
in  composition  of  amyloid  of  different  origins. 

Krawkow  studied  these  reactions  with  pure,  isolated  amyloid, 
and  found  evidence  that  the  iodin  reaction  depends  upon  the 
physical  properties  of  the  amyloid,  while  the  methyl-violet 
stain  is  a  chemical  reaction,  and  hence  the  iodin  reaction  is 
much  the  more  readily  altered  or  lost.  As  Dickinson l  says, 
amyloid  stains  writh  iodin  simply  as  if  it  absorbed  the  iodin 
more  than  does  the  surrounding  tissue.  The  methyl-violet 
reaction  is  due  to  the  dye  forming  a  compound  with  the  chon- 
droitin-sulphuric  acid,  for  Krawkow  found  that  these  substances 
unite  with  one  another  to  form  a  rose-red  precipitate.  Schmidt 
found  that  implanted  pieces  of  amyloid  lost  their  iodin  reaction 
as  they  underwent  autolysis,  while  the  methyl-violet  reaction 
was  still  very  distinct.2  It  is  evident,  therefore,  that  iodin  is 
not  by  itself  a  specific  stain  for  amyloid,  especially  as  glycogen 
gives  a  similar  reaction,3  while  true  amyloid  may  not  react. 

1  Allbutt's  System,  vol.  3,  p.  225. 

2Litten  (Verb.  Deut.  Path.  Gesell.,  1904  (7),  47)  states  that  thionin  and 
kresyl-violet  are  the  most  specific  stains  for  amyloid,  which  they^  color  blue; 
whereas  methyl-violet  stains  red  not  only  amyloid  but  also  mucin,  mast  cell 
granules,  and  the  ground  substance  of  cartilage,  v.  Gieson's  stain  usually 
colors  amyloid  pale  yellow,  and  hyalin  red. 

3  See  Wichmann,  Ziegler's  Beitr.,  1893  (13),  487. 


THE  ORIGIN  OF  AMYLOID  351 

THE  ORIGIN  OF  AMYLOID 

This  question  has  not  been  at  all  cleared  up  as  yet  by  the 
advances  made  in  our  knowledge  of  the  chemistry  of  amyloid 
substance.  The  fact  that  chondroitin-sulphuric  acid  is  a  char- 
acteristic constituent  suggests  that  this  body  may  be  liberated 
in  considerable  amount  during  the  destructive  processes  to 
which  amyloidosis  is  usually  secondary ;  this  idea  is  further 
supported  by  the  fact  that  amyloidosis  occurs  particularly  after 
chronic  suppuration  in  bone  and  lungs,  both  of  which  tissues, 
according  to  Krawkow,  contain  chondroitin-sulphuric  acid. 
This  idea  was  not  substantiated,  however,  by  the  experiments 
made  by  Oddi  and  by  Kettner,1  who  fed  and  injected  into  animals 
large  quantities  of  the  sodium  salt  of  chondroitin-sulphuric  acid 
without  producing  amyloid  changes.  Unpublished  experiments 
of  the  writer  with  the  same  material,  as  well  as  with  ground- 
up  cartilage  and  with  mucin,  were  equally  unsuccessful.  As  it 
is  possible  to  cause  amyloidosis  experimentally  in  animals, 
especially  chickens  and  rabbits,  by  causing  protracted  suppura- 
tion or  chronic  intoxication  with  bacterial  filtrates,  these  nega- 
tive results  speak  strongly  against  the  idea  of  a  transportation 
of  chondroitin-sulphuric  acid,  but  do  not  determine  it  finally. 
Especially  important  in  this  respect  is  the  extreme  difficulty  of 
producing  amyloid  experimentally,  for  in  only  a  certain  proportion 
of  cases  are  the  experiments  positive  (in  but  about  one-third  of 
Davidsohn's2 100  trials ;  and  many  other  experimenters  have  been 
much  less  successful3).  Davidsohn,  failing  always  to  get  amyloid 
experimentally  after  the  spleen  had  been  removed,  suggests  that 
this  organ  (in  which  amyloid  is  usually  earliest  and  most  abun- 
dantly observed)  produces  an  enzyme,  which  causes  a  precipitation 
of  amyloid  in  the  tissues  from  a  soluble  precursor  brought  in 
the  blood  from  the  site  of  cell  destruction.  Schmidt 4  gives  an 
excellent  discussion  of  the  various  features  of  amyloidosis,  and 
also  considers  it  probable  that  some  enzymatic  action  causes  a 
precipitation  or  coagulation  of  some  substance  in  the  tissue- 
spaces  or  lymph- vessels.  Amyloid  is  never  deposited  in  the 
cells  themselves,  and  it  seems  to  be  now  generally  considered 
that  the  amyloid  material  is  infiltrated  in  the  form  of  a  soluble 
modification  or  precursor,  and  that  it  is  not  manufactured  in 
the  organ  where  it  is  found.  It  is  an  interesting  fact  that  a 

1  Arch.  exp.  Path.  u.  Pharm.,  1902  (47),  178. 

2  Verb.  Deut.  Path.  Gesell.,  1904  (7),  39. 

3 See  Tarchetti,  Deut.  Arch.  klin.  Med.,  1903  (75),  526. 
*  Verb.  Deut.  Path.  Gesell.,  1904  (7),  2. 


352  RETROGRESSIVE  PROCESSES 

practically  identical  substance  is  formed  in  all  tissues  and  in  all 
species  of  animals,  even  when  the  cause  is  quite  different. 
Whether  the  precursors  are  brought  to  the  organ  in  solution, 
or  in  leucocytes,  is  unknown — probably  the  former.  The 
hypothesis  that  amyloid  is  formed  from  disintegrating  red  cor- 
puscles is  probably  incorrect.  It  is  also  quite  certain  that  it  is 
not  of  bacterial  origin,  for  amyloidosis  has  been  produced  by 
chronic  intoxication  with  aseptic  materials  (rennin),1  and  it  is 
also  produced  by  the  most  varied  species  of  bacteria  and  by 
their  toxins,  although  the  staphylococcus  is  usually  most  effective 
in  experimental  work.2  Neither  is  suppuration  absolutely  essen- 
tial, for  injection  of  toxins  alone  (e.  g.,  in  preparing  diphtheria 
antitoxin 3 ),  without  suppuration,  may  produce  amyloidosis,  as 
also  frequently  do  syphilis  without  suppuration  and,  less  often, 
many  other  non-suppurative  conditions  (e.  g.,  tumors). 

I/ocal  amyloid  accumulations 4  are  of  some  interest  in 
considering  the  genesis  of  the  usual  generalized  form.  They 
occur  particularly  as  small  tumors  in  the  larynx,  bronchi,  nasal 
septum,  and  eyelids ;  as  all  these  tissues  are  normally  rich  in 
chondroitin-sulphuric  acid,  it  seems  probable  that  the  amyloid 
arises  from  a  local  overproduction  of  chondroitin-sulphuric 
acid,  which  becomes  bound  with  proteids  in  situ.  This  makes 
it  seem  more  probable  that,  in  spite  of  the  lack  of  positive 
experimental  evidence,  general  amyloidosis  is  due  to  liberation 
of  excessive  quantities  of  chondroitin-sulphuric  acid  in  the 
sites  of  tissue  destruction. 

Another  form  of  local  amyloid  is  seen  particularly  in  the 
regional  lymph-glands  of  suppurating  areas ;  e.  g.,  the  lumbar 
glands  in  vertebral  caries,  the  axillary  glands  in  shoulder-joint 
suppuration.  This  local  amyloidosis  is  undoubtedly  due  simply 
to  the  fact  that  these  glands  receive  first,  and  in  largest  amounts, 
the  cause,  whatever  it  may  be,  of  the  amyloid  production.5 

Corpora  amylacea  will  be  found  discussed  under  "Concre- 
tions" (Chap.  xv). 

1  Schepilewsky,  Cent.  f.  Bakt,  1899  (25),  849. 

2  In  a  series  of  experiments  directed  to  ascertain,  if  possible,  which  constitu- 
ent of  pus  might  be  the  cause  of  amyloid  formation,  I  was  unable  to  secure 
amyloid  by  protracted  intoxication  of  rabbits  by  Witte's  "peptone,"  which 
consists  chiefly  of  proteoses  (Trans.  Chicago  Path'Soc.,  3903  (5),  240). 

3Zenoni,  liiforma  Med.,  1901  (2),  698. 

4 See  Edens,  Virchow's  Arch.,  1905  (180),  346. 

5  Quite  unexplained  is  the  cause  of  the  rarely  observed  localization  of 
amyloid  in  the  wall  of  the  urinary  bladder.  See  Lucksch  (Verh.  Deut.  path. 
Gesell.,  1904  (7),  34). 


HYALINE  DEGENERATION  353 


HYALINE  DEGENERATION1 

Much  confusion  concerning  this  condition  may  be  avoided  if 
we  appreciate  that  the  term  hyaline  indicates  a  certain  physical 
condition,  which  may  be  exhibited  by  many  substances  of  widely 
different  nature  and  origin.  There  is  no  one  chemical  compound, 
"  hyalin"  which,  accumulating  in  cells  or  tissues,  produces  a 
hyaline  appearance.  The  limits  of  the  application  of  the  term 
"  hyaline  degeneration,"  even  to  histological  findings,  is  not 
agreed  upon,  but  in  general  it  is  used  to  apply  to  clear,  homo- 
geneous, pathological  substances  that  possess  a  decided  affinity 
for  acid  stains,  such  as  eosin  or  fuchsin.  Somewhat  similar 
substances,  usually  of  epithelial  origin,  which  do  not  take  either 
these  or  basic  stains  strongly,  are  usually  called  "colloid." 
We  may  properly  consider  that  pathological  hyalin  can  be 
divided  into  two  chief  classes  according  to  its  origin :  (1)  con- 
nective-tissue hyalin ;  (2)  epithelial  hyalin. 

Connective-tissue  hyalin  is  characterized,  like  amyloid, 
by  being  deposited  in  or  among  the  fibrillar  substance  of  con- 
nective tissues,  and  not  within  the  cells  themselves,  but  there 
are  undoubtedly  several  different  sorts  of  chemical  substances 
responsible  for  various  forms  of  connective-tissue  hyalin.  One 
form  is  closely  associated  with  amyloid,  being  found  in  organs 
showing  amyloid  degeneration,  or  in  other  tissues  in  the  same 
body.  In  experimentally  produced  amyloidosis  in  animals  it 
has  been  shown  that  such  a  hyaline  substance  may  appear  before 
the  amyloid,  which  eventually  replaces  it ;  hence,  it  has  been 
suggested  that  hyalin  is  a  precursor  of  amyloid.  Such  hyalin 
differs  from  true  amyloid  only  in  its  failure  to  give  the 
characteristic  staining  reaction  of  amyloid ;  in  all  other  respects, 
e.  g.,  cause,  location,  termination,  it  is  the  same.  As  it  has 
been  shown  (see  preceding  section)  that  the  staining  properties 
of  amyloid  are  very  inconstant,  it  is  probable  that  the  above- 
described  variety  of  hyalin  is  merely  an  incompletely  developed, 
or  occasionally  a  retrogressively  altered  amyloid.  However,  it 
is  probably  not  necessary,  as  some  authors  have  thought,  that 
amyloid  should  always  pass  through  this  hyaline  stage  in  its 
formation. 

Quite  different,  without  doubt,  is  the  form  of  hyalin  observed 
in  scar  tissue.  This  variety  develops  almost  constantly  in  any 
scar-tissue  after  the  blood-supply  has  been  reduced  to  a  mini- 
mum through  contraction,  and  is  seen  characteristically  in  the 
corpora  fibrosa  of  the  ovary,  fibroid  glomerules  in  chronic 

1  General  literature,  see  Lubarsch,  Ergeb.  allg.  Path.,  1897  (4),  449. 
23 


354  RETROGRESSIVE  PROCESSES 

nephritis,  thickened  pleural,  pericardial,  and  episplenitis  scars, 
etc.  Such  hyaline  substance  occurs  independent  of  the  usual 
causes  of  amyloid,  affects  only  abnormal  fibrous  tissue,  never 
changes  into  amyloid,  and  is  prone  to  undergo  calcification — it 
surely  has  no  close  chemical  relation  to  the  form  of  hyalin  that 
does  become  amyloid.  Presumably,  it  is  similar  in  nature 
to  the  collagen  of  normal  fibrous  tissue  intercellular  substance, 
which  has  undergone  physical  rather  than  chemical  changes  into 
a  homogeneous  hyaline  substance.  For  its  physiological  proto- 
type it  has  the  thick  "  collagenous  "  fibers  of  the  subcutaneous 
connective  tissue. 

Probably  of  quite  different  origin  is  the  hyalin  that  develops 
from  elastic  tissue,  as  seen  best  in  the  thick-walled,  partly  oblit- 
erated arteries  of  the  senile  spleen ;  and  less  characteristically  in 
the  early  stages  of  arteriosclerosis,  since  here  the  preceding  form 
of  connective-tissue  hyalin  may  also  occur.  Although  arterial 
elastic  tissue  is  related  chemically  to  amyloid,  these  hyaline  ves- 
sels do  not  develop  the  usual  amyloid  reaction,  but  remain  more 
or  less  of  the  specific,  elastic  tissue  stains.  Presumably  this 
form  of  hyalin  is  an  increased  and  physically  altered  elastin.1 

Epithelial  hyalin  occurs  within  the  cells,  and  includes 
substances  of  presumably  widely  diverse  chemical  nature,  from 
the  keratin  of  squamous  epithelium  to  the  small  intracellular 
hyaline  granules  of  carcinoma  and  other  degenerating  cells  (Rus- 
sell's fuchsin  bodies2).  Extracellular  substances  of  hyaline 
character,  but  of  unknown  composition,  may  also  be  produced 
by  epithelium  ;  e.  g.,  hyaline  casts  in  the  renal  tubules. 

Many  other  pathological  materials  of  widely  differing  nature 
may,  under  certain  conditions,  assume  a  hyaline  appearance ; 
e.  g.j  fibrinous  exudates  and  thrombi,  degenerated  muscle-fibers 
(Zenker's  or  "  waxy  "  degeneration),  tumor-cells  (cylindroma), 
etc.  In  all  of  these  the  chemical  nature  of  the  parent  substance 
or  substances  is  probably  much  less  altered  than  its  physical 
appearance,  but  whether  the  change  is  related  to  the  process  of 
proteid  coagulation  or  not  is  unknown. 

COLLOID  DEGENERATION 

This  term,  also,  has  a  very  indefinite  meaning,  and  is  applied 
to  many  different  conditions  by  various  authors.  Thus,  v. 
Recklinghausen  includes  under  this  name  amyloid,  epithelial 
hyaline,  and  mucoid  degeneration.  Marchand  includes  hyaline 
connective-tissue  degeneration,  and,  also,  as  do  most  other 

1  See  Schmidt,  Verb.  Deut.  path.  Gesell.,  1904  (7),  2. 

2  Literature,  see  Hektoen,  Progressive  Med.,  1899  (ii),  241. 


COLLOID  DEGENERATION  355 

writers,  the  mucoid  degeneration  of  carcinoma.  Ziegler  rightly 
protests  against  the  inclusion  of  mucin  under  this  heading,  but 
includes  the  corpora  araylacea.  On  account  of  the  discovery 
by  Baumann  of  the  specific  chemical  nature  of  thyroid  colloid 
it  becomes  particularly  unfortunate  that  the  term  "  colloid  "  has 
such  a  wide  and  uncertain  application.  It  would  seem  that  the 
safest  view  to  take  is  that  the  word  colloid  is  merely  morphologic- 
ally and  macroscopically  descriptive  of  certain  products  of  cell 
activity  or  disintegration,  which  have  nothing  in  common 
except  the  fact  that  they  form  a  thick,  glue-like  or  gelatinous, 
often  yellowish  or  brownish  substance.  There  is  no  one  definite 
substance  colloid,  according  to  the  usual  usage  of  the  word  in 
pathological  literature,  but  many  different  proteid  substances 
may  assume  the  appearance  to  which  the  name  "  colloid  "  is 
given.  Looking  at  the  matter  in  this  way,  we  must  recognize 
as  the  usual  "colloid"  substances,  the  following  chemical 
bodies : 

Thyroid  colloid,  the  physiological  prototype  of  the  group. 
This  consists  of  a  compound  of  globulin  with  an  iodin-contain- 
ing  substance,  thyroiodin,  the  compound  proteid  being  called  by 
Oswald  iodothyreoglobulin.  It  occurs  pathologically  only  in 
cystic  and  similar  changes  in  the  thyroid  or  accessory  thyroids. 
Being  a  specific  product  of  the  thyroid  (and  perhaps  of  the 
hypophysis)  with  definite  physiological  properties,  it  manifestly 
has  only  a  morphological  relation  to  the  other  forms  of  colloid 
found  in  degenerating  tumors,  etc.  (The  nature  of  thyroid 
colloid  is  discussed  more  fully  under  "  Diseases  of  the  Thy- 
roid," Chap,  xx.) 

Mucin,  when  secreted  in  closed  cavities,  as  in  tumors,  where 
it  becomes  thickened  by  partial  absorption  of  the  water,  may 
take  on  a  "  colloid  "  appearance  while  retaining  its  chemical  and 
tinctorial  characteristics.  This  is  particularly  observed  in  the 
"  colloid "  carcinomas  which  arise  especially  from  the  mucous 
membrane  of  the  alimentary  tract.  This  substance  is,  of 
course,  quite  specific  both  in  its  chemical  nature  and  its  origin 
from  specialized  epithelial  cells,  and  the  process  should  properly 
be  considered  as  a  "  mucoid  degeneration." 

Psetldomucin,  which  differs  from  mucin  in  not  being  pre- 
cipitated by  acetic  acid,  is  a  common  component  of  ovarian 
cysts,  and  when  somewhat  concentrated  by  absorption  of  water, 
forms  a  "  typical  colloid."  Because  it  is  alkaline,  this  form  of 
colloid  tends  to  stain  rather  with  the  acid  dyes  (eosin,  fuchsin, 
etc.),  while  true  mucin  stains  with  basic  dyes.  Several  varieties 
of  pseudomucin  have  been  described  by  Pfannenstiel,  and  their 


356  RETROGRESSIVE  PROCESSES 

properties  will  be  considered  more  fully  in  the  section  on  "  Ovar- 
ian Tumors  "  ( Chap.  xvii).  The  clear,  glassy,  yellowish  sub- 
stance contained  in  small  cavities  of  ovarian  tumors,  which  is 
usually  called  "colloid/'  consists  of  nearly  pure  pseudomucin. 
All  these  substances  yield  a  reducing  substance  on  boiling  with 
acids,  which  is  a  nitrogen-containing  body,  glucosamin.1 

Simple  proteids  (e.  g.,  serum-globulin,  serum-albumin, 
nucleo-albumin,  etc.)  may,  when  in  solution  in  closed  cavities, 
become  concentrated  through  absorption  of  water  until  they 
produce  the  physical  appearance  of  "  colloid."  Probably  the 
colloid  contents  of  dilated  renal  tubules,  cavities  in  various 
mesoblastic  tumors,  etc.,  are  produced  in  this  way. 

MUCOID  DEGENERATION 

Mucin,  in  its  typical  form,  is  a  compound  proteid,  consisting 
of  a  proteid  radicle  and  a  nitrogen-containing  carbohydrate, 
glucosamin.  Hence,  when  boiled  with  acids,  mucin  yields  a 
substance  reducing  Fehling's  solution.  Mucin  is  acid  in  reac- 
tion, probably  because  of  the  presence  of  chondroitin-sulphuric 
acid  (at  least  in  some  varieties  of  mucin),  and,  therefore,  is 
characterized  microchemically  by  staining  with  basic  dyes.  It 
is  readily  dissolved  in  very  weak  alkaline  solutions,  is  pre- 
cipitated by  acetic  acid,  and  its  physical  properties  when  in 
solution  are  quite  characteristic.  The  term  mucin,  however, 
probably  covers  a  number  of  related  but  distinct  bodies.  Some, 
such  as  the  pseudomucins,  are  readily  distinguished  by  not  being 
precipitated  by  acetic  acid,  and  by  being  alkaline  in  reaction ; 
others  yield  reducing  substances  without  previous  decomposition 
with  acids  (paramucin)  ;  while  even  among  the  "  true  "  mucins 
certain  differences  in  solubility  exist.2 

In  the  mammalian  body  we  find  mucin  occurring  in  two 
chief  localities  :  (1)  as  a  product  of  secretion  of  epithelial  cells  ; 
(2)  in  the  interstices  of  connective  tissue,  especially  of  tendons. 
(The  resemblance  of  synovia}  fluid  to  mucin  is  more  physical 
than  chemical.)  There  is  also  evidence  that  mucin  or  a  related 
body  constitutes  the  cement  substance  between  all  the  body- 
cells.  Corresponding  to  these  two  chief  sources  of  mucin  we 
find  mucoid  degeneration  occurring  as  distinct  processes  in 
mucous  membranes  (or  tissues  derived  therefrom)  and  in  con- 
nective tissue. 

1  Zangerle,  Munch,  med.  Woch.,  1900  (47),  414. 

2  For  special  consideration  see  Cutter  and  Gies,  Amer.  Jour.  Physiol.,  1901 
(6),  155. 


MUCOID  DEGENERATION  357 

Epithelial  Mucin. — As  epithelial  mucin  represents  a  dis- 
tinct product  of  specialized  cells,  it  is  questionable  if  the  ordi- 
nary application  of  the  term  degeneration,  in  the  sense  of  the 
conversion  of  cell-protoplasm  into  mucin,  is  correct.  Certainly 
the  mucin  formation  of  catarrhal  inflammation  is  merely  an 
excess  of  a  normal  secretion,  and  the  degenerative  changes  that 
may  be  present  in  the  epithelial  cells  are  produced  by  the  cause  of 
the  inflammation,  and  are  not  dependent  upon  mucin  formation. 
Even  in  the  extreme  example  of  mucoid  degeneration  seen  in 
carcinomas  derived  from  mucous  membranes  (the  so-called  "col- 
loid cancers  "),  the  epithelial  degeneration  is  not  necessarily  to 
be  interpreted  as  a  conversion  of  cell-cytoplasm  into  mucin, 
but  is  largely  due  to  the  pressure  of  secreted  mucin  upon  the 
cells  within  the  confined  spaces  of  the  tumor.  The  mucin  in 
these  forms  of  mucoid  degeneration  is  chemically  the  same  as 
the  normal  mucin  coming  from  the  same  source,  but  mixed  with 
larger  or  smaller  quantities  of  other  proteids  derived  from  cell 
degeneration  or  from  vascular  exudates.  (The  stringy,  mucin- 
like  substance  seen  in  some  purulent  exudates  is  probably  com- 
posed largely  of  nucleoproteids  and  nucleo-albumins  derived 
from  the  degenerating  leucocytes,  and  is  not  true  mucin.) 

Connective-tissue  Mucin. — Excessive  formation  of  con- 
nective-tissue mucin  is  observed  most  characteristically  in  myx- 
edema  ( q.  v.  ),  but  may  also  occur  in  connective  tissues  that  are 
poorly  nourished  or  otherwise  slightly  injured  ;  it  is  seen  partic- 
ularly in  the  connective  tissues  surrounding  the  epithelial  ele- 
ments in  adenomas  and  carcinomas.  Connective-tissue  tumors 
(myxosarcoma,  myxofibroma,  or  myxoma)  may  also  show  a 
great  quantity  of  mucinous  intercellular  substance,  but  many 
of  the  so-called  myxomas  are  in  reality  merely  edematous 
fibromas  or  polypoid  tumors,  in  which  the  resemblance  to  true 
myxoma  is  largely  structural  rather  than  chemical.  This  form 
of  mucoid  degeneration  seems  to  be  merely  a  reversion  to  the 
fetal  type  of  connective  tissue,  which  is  characterized,  as  in  the 
umbilical  cord,  by  an  excessive  accumulation  of  a  mucin-con- 
taining  fluid  intercellular  substance,  and  a  paucity  of  collagen- 
ous  fibrillar  structure.  Apparently,  when  connective  tissue 
reverts  to  an  embryonal  type,  either  from  intrinsic  causes  (tumor 
formation),  or  when  the  nourishment  is  insufficient,  or  possibly 
when  the  normal  stimulus  to  cell  growth  is  absent  (myxedema), 
the  mucoid  characteristics  of  fetal  tissue  reappear. 

The  presence  of  mucin  in  the  tissues  seems  to  cause  no 
reaction,  and  its  absorption  causes  no  harm.  Rabbits  that  I 
injected  with  large  quantities  of  pure  tendon  mucin  almost  daily 


358  RETROGRESSIVE  PROCESSES 

for  two  to  four  months,  showed  absolutely  no  deleterious  effects, 
either  locally  or  constitutionally.1  Some  of  the  French  authors 2 
claim  that  mucin  possesses  a  slight  bactericidal  power.  On  the 
other  hand,  Rettger3  and  others  have  found  an  apparently 
typical  mucin  produced  by  certain  varieties  of  bacteria. 

GLYCOGEN  IN  PATHOLOGICAL  PROCESSES 

It  seems  probable  that  all,  or  nearly  all,  cells  contain  larger 
or  smaller  quantities  of  glycogen,  but  it  may  be  insufficient  in 
amount  to  be  detected  either  microscopically  or  chemically. 
Glycogen  seems  to  be  formed  within  the  cells  from  the  sugar 
of  the  blood,  through  a  process  of  dehydration  and  polymeri- 
zation, and  to  be  reconverted  whenever  necessary  into  sugar,  by 
a  reverse  process  of  hydrolysis.  It  is  quite  possible  that  both  of 
these  processes  represent  merely  the  reversible  action  of  an  intra- 
cellular  enzyme,  but  this  has  not  been  established.  We  do 
know,  however,  that  soon  after  death  the  intracellular  glycogen 
is  rapidly  converted  into  dextrose.4 

Properties  of  Glycogen. — Glycogen  is  frequently  called  an  ''animal 
starch,"  having  the  same  general  composition  as  the  starches  (C6H1005)X, 
and  apparently,  like  the  starches,  it  represents  a  relatively  insoluble  rest- 
ing stage  of  sugar  in  the  course  of  metabolism,  It  is  readily  soluble  in 
water,  forming  an  opalescent,  colloidal  solution,  and,  therefore,  has  no 
effect  on  osmotic  pressure,  and  it  is  not  diffusible. 5  Because  of  its  solu- 
bility and  the  rapidity  with  which  postmortem  change  to  dextrose 
occurs,  specimens  that  are  to  be  examined  microscopically  for  glycogen 
must  be  hardened  while  very  fresh  in  strong  alcohol,  in  which  glycogen  is 
insoluble.6  One  of  the  most  characteristic  reactions  is  the  port-wine  color 
given  by  glycogen  when  treated  with  iodin  ;  this  reaction  may  be  applied 
microscopically,  solution  of  the  glycogen  being  avoided  by  having  the 
iodin  dissolved  in  a  solution  of  gum  arabic  or  in  glycerin.  Salivary 
ptyalin  rapidly  converts  glycogen  into  glucose,  and  this  reaction  may 
also  be  used  microscopically  to  prove  that  suspected  granules  are 
glycogen. 

1  Levin  (Med.  Record,  1900  (57),  184)  claims  that  mucin  injected  into  thy- 
roidectomized  rabbits  is  very  poisonous  for  them,  while  not  harming  normal 
rabbits. 

2  Arloing,  Compt.  Rend.  Soc.  Biol.,  1902  (54),  306,  and  1901  (53),  1117. 

3  Jour.  Med.  Research,  1903  (10),  101. 

4  Literature  concerning  physiology  of  glycogen  by  Pfliiger,  Pfliiger's  Arch., 
1903  (96),  398;  and  Cremer,  Ergeb.  der  Physiol.,  1902  (1,  Abt.  1),  803. 

5  See  Gatin-Gruzewska,  Pfliiger's  Arch.,  1904  (103),  282. 

6  According  to  Helman  (Cent.  f.  inn.  Med.,  1902  (23),  1017),  glycogen  may 
be  found  in  specimens  preserved  in  alcohol  as  long  as  fifteen  years. 


PHYSIOLOGICAL   OCCURRENCE  OF  GLYCOOEN      359 


PHYSIOLOGICAL  OCCURRENCE 

According  to  Gierke,1  the  Dormal  glycogen  of  cells  resembles 
fat  in  that  part  of  it  disappears  during  starvation,  while  the  rest 
cannot  be  removed  in  this  way  and  probably  is  something  more 
than  a  reserve  food-stuff.  In  distribution  glycogen  somewhat 
resembles  fat,  being  abundant  in  the  liver2  and  muscles,  but 
Gierke  considers  that  the  microscopic  evidence  of  the  quantity 
of  glycogen  present  in  the  cell  agrees  better  with  the  results  of 
actual  chemical  analysis  than  is  the  case  with  fat.  Neither  iodin 
nor  Best's  carmin  stain  are  absolutely  specific  for  glycogen,  but 
Gierke  believes  that  we  may  safely  consider  a  substance  as 
glycogen  when  it  is  homogeneous,  rather  easily  soluble  in  water 
and  more  so  in  saliva,  gives  the  usual  iodin  reaction,  and  stains 
bright  red  with  Best's  carmin  solution.3  With  these  controls, 
the  microscopic  findings  were  found  to  agree  closely  with  the 
results  of  direct  chemical  analysis,  and  glycogen  was  found 
microscopically  visible  in  muscle,  liver,  lung,  heart,  uterus,  and 
skin  (but  not  in  the  brain,  where  it  may  be  demonstrated  chemi- 
cally in  minute  quantities). 

Glycogen  is  especially  abundant  in  fetal  tissues,  but  it  is  not 
present  in  all  fetal  cells,  nor  is  it  always  most  abundant  in  the 
most  rapidly  growing  tissues.  Although  both  fat  and  glycogen 
are  quite  abundant  in  fetal  muscle  and  liver  tissues,  the  liver  of 
early  embryos  does  not  contain  either.4  In  extra-uterine  life 
glycogen  is  relatively  less  abundant ;  invertebrates  and  the 
lower  vertebrates  have  more  than  the  higher  forms.  In  mam- 
malian adults  the  liver  and  muscle  contain  the  most  glycogen, 
cartilage  standing  next,  and  it  is  also  present  in  squamous 
epithelium  (particularly  the  middle  layers),  but  not  in  slightly 
stratified  (cornea),  transitional,  or  cylindrical  epithelium.  The 
normal  lung  is  microscopically  glycogen-free  (except  for  its 
cartilage  and  muscle),  as  also  are  the  nervous  system,  pancreas, 
salivary  glands,  thyroid,  hypophysis,  bone-marrow,  and  adrenals ; 
normal  human  kidneys  do  not  seem  to  show  glycogen,  but  it 
may  be  present  in  the  kidneys  of  mice,  rabbits,  and  cats. 

1K  complete  summary  of  all  the  literature  to  the  end  of  1904  is  given  in 
Gierke's  article  in  Ziegler's  Beitr.,  1905  (37),  502;  hence  references  included 
by  Gierke  will  not  generally  be  given. 

2  In  the  livers  of  two  executed  criminals  Gamier  (Compt.  Rend.  Soc.  BioL, 
1906  (60),  125)  found  respectively  4  per  cent,  and  2.79  per  cent,  of  glycogen. 

3  A  special  staining  method  is  recommended  by  Driessen,  Cent.  f.  Path., 
1905  (16),  129. 

*  Adamoff  (Zeit.  f.  BioL,  1905  (46),  288)  contests  the  idea  that  the  amount 
of  glycogen  is  in  direct  relation  to  growth  energy. 


360  RETROGRESSIVE  PROCESSES 

There  is  very  little  in  heart  muscle  or  testicle,  and  none  in  the 
ovaries  and  corpus  luteum  or  in  the  mammary  glands,  although 
it  may  be  present  in  their  fat-cells.  Glycogen  is  most  abundant 
in  the  uterus  at  the  time  of  child-birth,  and  is  abundant  in  the 
placenta.  After  pancreas  extirpation,  Fichera  !  observed  a  dis- 
appearance of  all  visible  glycogen,  except  a  little  in  the  cartilage 
and  stratified  epithelium ;  hence  he  considers  the  glycogen- 
content  as  a  function  of  cell  nourishment.  Fat  and  glycogen 
often  occur  together  (which  is  contrary  to  Rosenfeld's  statement), 
although  one  may  be  present  without  the  other  (Gierke). 

There  has  been  some  diversity  of  opinion  as  to  whether  gly- 
cogen occurs  as  granules  in  the  living  cell,  or  whether  the  gran- 
ules are  formed  from  a  homogeneous  substance  by  hardening 
fluids.  In  view  of  the  clear-cut,  definite  spaces  it  may  leave  in 
cells  when  dissolved  out,  glycogen  probably  occurs  as  granules, 
especially  when  present  in  abnormally  large  quantities.  It  has 
been  suggested  that  the  intraepithelial  hyaline  bodies  (Russell's 
fuchsin  bodies)  are  glycogenic,  which  idea  is  probably  not  cor- 
rect. Habershon  has  also  suggested  that  eosinophile  granules 
are  either  glycogen  or  related  to  it.  The  presence  of  glycogen 
in  the  cells  seems  to  cause  no  injury  to  the  cytoplasm,  and  if  it 
again  disappears,  the  cells  become  quite  normal.2 

GLYCOGEN  IN  PATHOLOGICAL  PROCESSES 

According  to  the  results  obtained  by  Fichera  and  Gierke,  it 
seems  probable  that  glycogen  accumulation  is  produced  under 
the  same  conditions  as  are  fatty  changes ;  i.  e.,  when  oxidation 
is  locally  or  generally  impaired.  Fat  and  glycogen  are,  there- 
fore, often  found  together  in  the  margins  of  infarcts  and  of 
tubercles,  and  in  heart  muscle  with  fatty  changes  due  to  severe 
anemia.  The  glycogen,  being  more  labile,  seems  to  disappear 
early  when  the  cells  become  necrotic,  and  hence  glycogen  is  not 
present  in  older  necrotic  areas  where  the  fat  still  persists.  (This 
probably  accounts  for  the  frequently  repeated  statement  that 
glycogen  and  fat  do  not  occur  together.)  Whether  the  glycogen 
can  be  transformed  into  fat,  perhaps  forming  an  intermediary 
stage  in  a  transformation  of  proteid  into  fat,  has  not  been  deter- 
mined, but  there  seems  to  be  little  doubt  that  it  is  infiltrated 

1  Ziegler's  Beitr.,  1904  (36),  273,  literature. 

2  Yet  Teissier  (Compt.  Kend.  Soc.  Biol.,  1900  (52),  790)  believes  the  amount 
normally  present  in  the  liver  is  strongly  bactericidal,  and  in  a  later  publication 
(tirid.,  1902  (54),  1098)  considers  that  it  is  toxic  to  liver-cells.     Wendelstadt 
(Cent.  f.  Bact.,  Abt.  1, 1903  (34),  831)  found  that  under  certain  conditions  gly- 
cogen impedes  hemolysis  by  normal  serum. 


GLYCOGEN  IN  PATHOLOGICAL  PROCESSES         361 

from  outside  the  cell,  and  not  formed  directly  from  degener- 
ated proteid.  It  seems  to  be  deposited  only  in  cells  that  are 
still  living,  although  it  can  become  split  up  in  dead  cells.  All 
cells,  but  especially  muscle-cells  and  leucocytes,  seem  able  to 
lay  up  glycogen  in  visible  amounts  under  certain  conditions. 
In  inflamed  areas  glycogen  is  found  both  in  tissue-cells  and 
leucocytes,  but  not  in  cells  showing  nuclear  degeneration  (Best, 
Gierke).  In  pneumonia  the  leucocytes  of  the  exudate,  and  to 
a  less  extent  the  alveolar  epithelium,  contain  glycogen  as  well 
as  fat. 

Glycogen  in  Tumors. — Glycogen  has  been  observed  fre- 
quently in  tumors.  Brault  believed  the  quantity  an  index  of 
rate  of  growth,  on  the  principle  that  glycogen  appears  most 
abundantly  in  embryonal  tissues,  and  therefore  in  tumors  the 
amount  of  glycogen  should  agree  with  the  degree  to  which  the 
cells  have  gone  back  to  the  embryonic  type.  Lubarsch  consid- 
ered that  only  tissues  normally  containing  glycogen  give  rise  to 
glycogen-containing  tumors.  Gierke  could  corroborate  neither  of 
these  ideas,  and  considers  that  glycogen  arises  in  tumors  under 
exactly  the  same  conditions  in  which  it  arises  in  other  tissues ; 
i.  e.j  when  cell  nutrition  and  oxidation  are  impaired.  Apparently, 
however,  both  the  embryonic  origin  and  local  retrogressive  changes 
determine  the  deposition  of  glycogen  in  tumors.  Glycogen  is  par- 
ticularly abundant  in  squamous  epithelium  of  epitheliomas  that 
have  gone  on  to  hornification ;  in  testicular  tumors,  hyperneph- 
romas,  endotheliomas,  choudromas,  and  myomas,  and  it  also 
occurs  in  the  connective  tissues  surrounding  tumors.  Of  1544 
tumors  of  all  sorts  examined  by  Lubarsch,1  447  (or  29  per 
cent.)  contained  glycogen  microscopically ;  fibromas,  osteomas, 
gliomas,  hemangiomas  were  always  free  from  glycogen ;  and 
lipomas  and  lymphangiomas  nearly  always.  Adenomas  are 
almost  equally  free  from  glycogen  (two  positive  in  260  speci- 
mens), while  it  was  constant  in  teratomas,  rhabdomyomas, 
hypernephromas,  and  chorioepitheliomas.  Fifty  and  seven- 
tenths  per  cent,  of  the  sarcomas  and  43.6  per  cent,  of  the  carci- 
nomas show  glycogen,  most  abundant  in  squamous-cell  epitheli- 
omas ;  columnar-celled  carcinomas  contain  glycogen  much  less 
often,  and  it  is  always  absent  in  "  colloid  cancers." 

Animal  parasites,  in  common  with  other  invertebrates, 
usually  show  abundant  quantities  of  glycogen.2  It  has  been 

1  Virchow's  Arch.,  1906  (183),  188. 

2  Elaborate  treatise  on  occurrence  of  glycogen  in  lower  animals  by  Barfurth, 
Arch,  mikros.   Anat,  1885   (25),  269;  also  Busch,  Arch,  internal,  physiol., 
1905  (3),  49;  Brault  and  Loeper,  Jour.  Phys.  et  Path.  Gen.,  1904  (6),  295 
and  720. 


362  RETROGRESSIVE  PROCESSES 

found  in  protozoa,  as  well  as  in  all  varieties  of  intestinal  worms. 
According  to  Barfurth,  nematodes  in  glycogen-free  animals  may 
contain  glycogen.  The  glycogen  is  found  chiefly  in  the  con- 
nective tissues  of  the  intestinal  parasites,  but  in  some  of  the 
nematodes  it  occurs  chiefly  in  the  sexual  organs  and  muscle- 
cells.  The  walls  of  hydatid  cysts  contain  much  glycogen, 
which  is,  perhaps,  related  to  the  usual  presence  of  sugar  in 
their  contents.  If  Habershon's  contention  is  correct,  that 
eosinophile  granules  are  related  to  glycogen,  we  may  have  here 
an  explanation  of  the  occurrence  of  eosinophilia  in  infection 
with  animal  parasites.  (See  also  "  Animal  Parasites,"  Chap,  v.) 

Glycogen  in  I/eucocytes. — The  occurrence  of  glycogen 
in  the  blood  has  aroused  much  interest,  particularly  in  relation 
to  its  diagnostic  value.  Many  leucocytes  contain  granules  that 
stain  with  iodin,  and  although  it  is  possible  that  these  are  not 
all  granules  of  glycogen,  yet,  for  the  most  part,  they  probably 
represent  this  substance  in  excessive  quantities.  The  granules 
are  observed  chiefly  in  the  polymorphonuclear  neutrophiles,  but 
also  in  large  and  small  mononuclear  cells ;  only  in  diabetes  do 
the  eosinophiles  contain  glycogen,  according  to  most  authors, 
but  Habershon  believes  that  eosinophile  granules  are  related  to 
or  identical  with  glycogen.  Occasional  granules  are  also  found 
free  (or  perhaps  contained  in  blood-platelets)  in  all  blood, 
whether  normal  or  pathological,1  whereas,  according  to  Locke, 
the  leucocytes  contain  the  granules  only  in  pathological  condi- 
tions. It  does  not  seem  to  be  settled  whether  the  glycogen  is 
taken  on  by  the  leucocytes  at  the  place  of  pathological  lesion, 
or  in  the  bone-marrow  under  the  influence  of  circulating  poi- 
sons, or  both.  Habershon  states  that  from  1  to  16  per  cent, 
of  all  leucocytes  normally  contain  glycogen  granules,  and 
Wolff  believes  that  the  glycogen  seen  in  leucocytes  repre- 
sents normal  glycogen  made  insoluble  through  injury. 

Locke  gives  the  occurrence  of  this  abnormal  iodin  staining 
of  the  leucocytes  (termed  iodophilia)  as  follows  :  "  Septic  condi- 
tions of  all  kinds,  including  septicemia,  abscesses,  and  local 
sepsis,  except  in  the  earliest  stages,  appendicitis  accompanied 
by  abscess  formation  or  peritonitis,  general  peritonitis,  empy- 
ema,  pneumonia,  pyonephrosis,  salpingitis  with  severe  inflam- 
mation or  abscess  formation,  tonsillitis,  gonorrheal  arthritis,  and 
hernia  or  acute  intestinal  obstruction  where  the  bowel  has 

1  Literature— Locke  and  Cabot,  Jour.  Med.  Research,  1902  (7),  25;  Locke, 
Boston  Med.  and  Surg.  Jour.,  1902  (147),  289;  Reich,  Beitr.  klin.  Chir., 
1904  (42),  277;  Kiittner,  Arch.  klin.  Chir.,  1904  (73),  438;  Gulland,  Brit. 
Med.  Jour.,  1904  (i),  880;  Habershon,  Jour.  Path,  and  Bact.,  1906  (11),  95; 
Wolff,  Zeit.  klin.  Med.,  1904  (51),  407. 


GLYCOGEN  IN  PATHOLOGICAL  PROCESSES         363 

become  gangrenous,  have  invariably  given  a  positive  iodophilia, 
and  by  its  absence  all  these  cases  can  be  ruled  out  in  diagnosis. 
In  other  words,  no  septic  condition  of  any  severity  can  be 
present  without  a  positive  reaction.  Furthermore,  the  disap- 
pearance of  the  glycogen  granules  in  the  leucocytes  in  from 
twenty-four  to  forty-eight  hours  following  crisis  with  frank 
resolution  in  pneumonia,  and  the  thorough  drainage  of  pus  in 
septic  cases,  is  of  considerable  importance." 

In  exudates  glycogen  is  found  in  the  leucocytes  as  long  as 
they  retain  their  vitality,  but  disappears  soon  after  retrogressive 
changes  begin ;  hence  it  is  not  usually  present  in  sterile  pus. 
Loeper l  made  quantitative  estimates  of  the  glycogen  in  exu- 
dates, finding  from  0.59-0.62  gram  per  liter  in  cellular  pneumo- 
coccus  pleural  effusion,  0.25  gm.  in  cellular  tuberculous  effusion, 
but  only  traces  in  serous  tuberculous  effusion  and  in  an  old 
tuberculous  pyothorax.  A  pneumonic  lung  contained  0.85  gm. 
of  glycogen  per  kilo,  and  traces  were  found  in  pneumonic 
sputum  and  in  the  contents  of  tuberculous  cavities.  When 
glycogen  solution  (1  per  cent.)  was  injected  into  the  peritoneal 
cavity,  the  endothelial  cells  and  invading  leucocytes  became 
loaded  with  glycogen  granules. 

Glycogenic  Infiltration  in  Diabetes. — It  is  in  diabetes, 
however,  that  the  most  marked  accumulations  of  glycogen  are 
found,  the  granules  frequently  fusing  in  the  cells  into  droplets 
larger  than  the  nucleus ;  when  dissolved  out  in  ordinary  micro- 
scopic preparations,  the  clear  round  space  left  is  exactly  like  the 
space  left  by  a  fat-droplet,  except  that  the  margins  show  a 
tendency  to  take  the  basic  stain  for  some  unknown  reason.  In 
even  the  most  extreme  cases,  however,  the  nucleus  is  well  pre- 
served. Glycogen  is  found  particularly  in  the  epithelium  of 
Henle's  tubules,  in  heart  muscle,  and  in  the  leucocytes,  whereas 
it  is  greatly  diminished  in  the  normal  storehouses  of  glycogen, 
the  liver  and  muscles.  Fiitterer  describes  masses  of  glycogen 
in  the  cerebral  capillaries,  resembling  an  embolic  process.  Sand- 
meyer  analyzed  the  organs  for  glycogen  in  a  case  of  diabetes, 
finding  the  following  amounts  in  percentage  of  organ  weight : 
liver,  0.613;  kidneys,  0.1158;  lungs,  0.0442;  spleen,  0.07. 
Experimental  diabetes  (pancreas  extirpation)  produces  a  marked 
glycogenic  infiltration. 

1  Arch.  Mdd.  Exp.,  1902  (14),  576. 


CHAPTER   XV 

CALCIFICATION,  CONCRETIONS,    AND 
INCRUSTATIONS 

CALCIFICATION  l 

Pathological  calcification  occurs  in  two  forms  :  one  is  a  pre- 
cipitation of  calcium  in  secretions  and  excretions  of  the  body ; 
the  other  is  the  deposition  of  calcium  salts  in  the  tissues  them- 
selves. The  former,  which  includes  not  only  concretions  in 
general,  but  probably  also  the  deposition  of  calcium  salts  in  the 
cells  and  tubules  of  the  kidney,2  both  in  disease  and  in  experi- 
mental calcification  after  certain  poisonings,  is  readily  enough 
explained  in  most  instances  by  recognizable  alterations  in  the 
composition  of  the  secretions,  which  lead  to  simple  chemical 
precipitations.  With  this  form  we  shall  deal  in  the  subsequent 
consideration  of  concretions,  but,  in  referring  to  calcification, 
shall  indicate  only  depositions  within  the  tissues. 

Relation  of  Calcification  to  Ossification. — In  normal 
ossification  we  have  to  deal  with  the  accumulation  of  lime  salts 
within  the  stroma  or  cells  of  a  tissue  that  has  usually  undergone 
certain  preparatory  changes  in  the  way  of  formation  of  a  more 
or  less  homogeneous  ground  substance,  but  has  not  suffered  a 
total  loss  of  vitality,  although  vitality  is  possibly  decreased. 
Pathological  calcification  is  similar,  in  so  far  as  we  have  to  deal 
with  deposition  of  much  the  same  salts  in  tissues  that  have 
suffered  either  total  or  partial  loss  of  vitality,  and  which  very 
frequently  indeed  are  hyaline.  What  appear  to  be  essential 
differences  are  these  :  (1)  In  calcification  the  lime  salts  always 
remain  in  clumps  and  masses,  often  fusing  to  greater  or  less 
degree,  but  never  with  the  diffuse  even  permeation  of  tissue  seen 
in  ossification.  (2)  All  the  cells  within  a  calcified  area,  if  not 
dead  at  the  beginning  of  the  process,  eventually  disappear  for 
the  most  part,  and  we  have  sooner  or  later  a  perfectly  inert 
mass,  practically  a  foreign  body,  instead  of  a  specialized  tissue 
as  in  ossification.  (3)  Ossification  is  accomplished  only  in 

1  Literature  and  re'sum^ :    Pfaundler,  Jahrb.   f.  Kinderheilk.,  1904  (60), 
123  ;  Wells,  Jour.  Med.  Research,  1906((14),  491. 

2  See  v.  Kossa,  Ziegler's  Beitr.,  1901  (29),  163. 

364 


CALCIFICATION 


365 


varieties  of  connective  tissue,  but  calcification  may  involve  any 
sort  of  a  cell,  provided  it  is  degenerated  sufficiently. 

Composition  of  the  Deposits  in  Calcification. — The 
composition  of  the  inorganic  salts  in  calcified  areas  in  the  body 
seems  to  be  practically  the  same,  if  not  identical,  whether  the 
salts  are  laid  down  under  normal  conditions  (ossification)  or 
under  pathological  conditions.  This  may  be  shown  by  a  table 
giving  the  proportion  of  inorganic  salts  found  by  analysis  of 
normal  bone,  and  the  proportion  found  in  calcified  materials : l 


Mg3(P04)2. 

CaC03. 

Ca8(P04)2. 

PATHOLOGICAL  CALCIFICATION. 
Bovine  tuberculosis        •               .... 

0.84 

128 

859 

«                « 

0.9 

131 

854 

«                     a 

1.2 

11.7 

864 

<  (softened  gland)  .... 
Human  tuberculosis    

1.5 
1.2 

7.6 
101 

90.6 

87.8 

Calcified  nodule  in  thyroid       

0.85 

13.4 

85.4 

Thrombus   human 

1  1 

11  9 

865 

NORMAL  OSSIFICATION. 
Human  bone  (Zalesky)      

1.04 

-i-128 

83.8 

"          "     (Carnot) 

1  57 

101 

874 

"          "      (Carnot) 

175 

92 

878 

Ox  bone  (Zalesky)                  .    .    . 

1  02 

861 

"       "     (Carnot)    ...                ... 

1  53 

11  9 

85  7 

Iron  may  be  present  in  pathological  calcification  as  it  is  in 
ossification.  According  to  Gierke,2  in  the  fetus  the  entire 
skeleton  contains  iron  as  far  as  it  has  calcified,  most  at  the 
points  of  active  ossification.  Iron  was  also  found  in  the  borders 
of  a  splenic  infarct,  in  a  thyroid  with  calcification  of  its  secretion, 
in  a  kidney  with  calcification  produced  by  sublimate  poisoning, 
in  calcified  ganglion-cells  of  the  brain,  and  in  some  psammomas 
and  a  psammosarcoma.  On  the  other  hand,  Gierke  could  find 
no  iron  in  calcified  atheromatous  arteries,  lymph-glands,  lung 
nodules,  and  common  petrefaction  strumas,  or  in  tumors  with 
bone  formation  as  well  as  those  with  calcified  degenerated 
particles.  The  significance  of  this  iron  and  the  nature  of  its 
union  are  both  unknown.  Pick 3  considers  that  in  certain  forms 
of  calcification  of  the  vessels  of  the  brain,  the  iron  exists  as  a 
calcium-iron-albuminate,  since  calcified  granules  in  the  vessels 
that  he  studied  gave  the  Berlin-blue  reaction  for  iron,  while 

1  Wells,  Loc.  cit. 

2  Virchow's  Arch.,  1902  (167),  318. 
3Keurol.  Centralb.,  1903  (22),  754. 


366   CALCIFICATION,   CONCRETIONS,   AND  INCRUSTATIONS 

after  decalcification  no  coloration  could  be  obtained.  S.  Ehrlich l 
states  that  elastic  fibers  in  the  vicinity  of  hemorrhages  take  up 
an  iron-containing  derivative  of  the  blood-pigment,  and  this 
acts  as  a  mordant  for  subsequent  calcium  deposition. 

Structure  of  Calcified  Areas. — As  before  mentioned, 
in  calcification  there  is  not  the  same  uniform  infiltration  of  the 
ground  substance  with  lime  salts  that  occurs  in  bone,  yet  the 
calcified  area  is  possessed  of  a  ground  substance  of  organic 
material  which  does  not  dissolve  in  acids  that  remove  the  salts. 
There  is  no  definite  ratio  between  the  lime  salts  and  this 
albuminoid  matrix,  however.  At  first  the  salts  occur  in 
granules,  which  may  become  fused  to  a  greater  or  less  degree. 
It  has  been  thought  by  some  that  the  deposition  occurs  in  the 
form  of  "  calcospherites." 

These  are  small  calcareous  bodies,  usually  of  concentric  structure, 
which  were  first  described  by  Harting.  They  appear  to  occur  widely 
distributed  in  normal  tissues,  both  animal  and  plant,  and  seem  to  be  the 
result  of  the  formation  of  insoluble  calcium  salts  in  the  presence  of 
some  organic  substances,  just  as  urinary  and  other  concretions  are 
formed  about  an  organic  nucleus.  If  calcium  chloride  and  soluble 
carbonates  are  allowed  to  combine  very  slowly  to  form  calcium  carbonate 
in  a  solution  of  egg-albumen,  these  or  indistinguishable  bodies  are  formed, 
which  on  being  dissolved  are  found  to  possess  an  organic  stroma  that 
exhibits  a  marked  affinity  for  any  pigmentary  substance  that  may  be 
present.  Apparently,  when  the  proper  concentration  exists,  the  salts  in 
crystallizing  hold  between  the  crystals  the  albuminous  substances  by 
which  they  are  surrounded.  Dastre  and  Morat  believe  that  the  sub- 
stratum is  lecithin,  which  others  have  found  occupying  a  similar  place 
in  prostatic  concretions.  Calcospherites  have  been  found  in  tumors, 
in  cystic  cavities,  and  in  bodies  with  beginning  decomposition.  It  may  be 
mentioned  in  passing  that  Littlejohn  2  observed  the  abundant  formation 
of  calcium  phosphate  crystals  in  bodies  that  had  been  immersed  for  some 
time  in  sea  water.  Oliver  has  found  calcospherites  in  the  tissues  of  a 
cancer  of  the  breast.  Pettit 3  found  calcospherites  in  a  sarcoma  of  the 
maxilla,  presenting  insensible  transitions  into  the  substance  of  the  osseous 
tissue,  and  he  suggests  the  possibility  that  the  calcospherite  formation 
may  be  related  to  the  formation  of  bone.  It  seems,  however,  that  they 
are  probably  more  related  to  the  formation  of  the  shells  of  invertebrates, 
which  are  largely  composed  of  carbonates  in  crystalline  structure  with  an 
organic  ground  substance  between  them,  and  very  little  phosphate  indeed. 

OCCURRENCE  OF  PATHOLOGICAL  CALCIFICATION 

As  far  as  we  know,  calcification  never  occurs  in  normal 
tissue,  except  in  the  formation  of  bone.  Often  the  infiltrated 
tissue  is  completely  dead,  as  in  infarcts,  organic  foreign  bodies, 

1  Cent.  f.  Pathol.,  1906  (17),  177. 

2  Edinburgh  Med.  Jour.,  1903  (13),  127. 

3  Arch.  d.  Anat.  Micros.,  1897  (1),  107. 


OCCURRENCE  OF  PATHOLOGICAL  CALCIFICATION  367 

caseous  areas,  and  particularly  in  old  inspissated  collections  of 
pus.  It  may  be  said  that  any  area  of  dead  tissue  that  is  not 
infected,  and  that  is  so  large  or  so  situated  that  it  cannot  be 
absorbed,  will  probably  become  infiltrated  with  lime  salts. 
Most  frequently  calcified,  next  to  totally  necrotic  tissues,  are 
masses  of  scar-tissue  that  have  become  hyaline  subsequent  to 
the  shutting  off  of  circulation  in  the  scar  by  contraction  of  the 
tissue  about  the  vessels.  Elastic  tissue  also  seems  prone  to  an 
early  calcification,  and  it  is  not  uncommon  to  see  the  elastic 
laminae  of  small  arteries  calcified  in  an  apparently  selective 
manner.  A  peculiar  form  of  calcification  is  that  frequently 
found  in  ganglion-cells  of  the  brain  which  have  become  degen- 
erated or  necrotic,  particularly  in  the  vicinity  of  old  hemor- 
rhages ;  the  cells  become  infiltrated  with  lime  salts  until  a 
complete  cast  of  the  cell,  with  dendrites  and  axis-cylinder  well 
impregnated,  is  formed.  The  calcification  of  renal  epithelium 
obtained  experimentally  by  ligation  of  the  renal  vessels  or  by 
the  administration  of  certain  poisons,  is  considered  by  some  to 
be  more  closely  related  to  the  formation  of  ordinary  urinary 
concretions  than  to  tissue  calcification ;  in  any  event,  because  of 
the  function  of  the  renal  tissues  to  excrete  calcium,  and  the 
continuous  bathing  of  the  cells  with  calcium-containing  urine, 
the  conditions  are  quite  different  from  what  they  are  in  ossifi- 
cation and  other  forms  of  pathological  calcification.  Calcifi- 
cation of  epithelial  cells  does  occur,  however,  and  seems  to 
be  preceded  by  hyaline  changes,  in  which  hyaline  substance 
the  calcium  is  later  deposited,  as  in  epithelial  pearls,  for 
example. 

LeNoir l  attempts  to  lay  down  a  law  of  calcification,  as  follows  : 
"  We  know  that  certain  pigments  are  fixed  first  in  the  tissues  possessing 
the  most  feeble  vitality.  Charrin  and  Carnot  have  shown  that  mineral 
poisons  (lead)  accumulate  by  choice  in  tissue  previously  altered.  The 
organism,  therefore,  seems  to  have  a  tendency  to  rid  itself  of  valueless 
or  toxic  compounds  in  tissues  where  nutrition  is  least  active.  Lime 
salts  do  not  form  an  exception  to  the  general  rule  ;  if  they  are  in  excess 
in  the  blood,  they  accumulate  in  the  cells  that  are  necrobiotic,  or  in 
cells  in  which  the  vitality  is  feeble,  and  there  are  deposited  in  an  in- 
soluble condition."  This  law  is  expressed  in  rather  too  metaphysical  a 
manner,  but  it  probably  contains  a  kernel  of  fact, 

Metastatic  Calcification. — What  is  perhaps  the  only  ex- 
ception to  the  rule  that  some  form  of  tissue  degeneration  is 
required  before  calcification  occurs  is  the  "  metastatic  calcification" 

1  Bouchard's  Path.  G£n6rale,  vol.  3,  pt.  2,  p.  650. 


368   CALCIFICATION,   CONCRETIONS,  AND  INCRUSTATIONS 

of  Virchow.1  In  conditions  with  much  destruction  of  bone, 
as  osteomalacia,  caries,  osteosarcoma,  etc.,  deposits  of  lime 
salts  have  been  found  distributed  diffusely  in  various  organs, 
particularly  in  the  lungs  and  stomach.  As  there  is  no  evidence 
that  these  organs  had  been  the  site  of  any  diffuse  tissue  necro- 
biosis  before  the  calcification  occurred,  it  seems  probable  that  the 
deposits  have  been  made  in  practically  or  quite  normal  organs, 
because  of  oversaturation  of  the  tissue  fluids  by  calcium  salts. 
The  fact  that  the  lung  and  stomach,  and  also  to  a  less  degree 
the  kidney,  are  picked  out,  suggests  that  the  calcification  is 
related  to  the  fact  that  in  these  same  organs  we  have  the 
excretion  of  acids  into  their  cavities,  which  leaves  the  fluids  in 
the  substance  of  the  organs  correspondingly  alkaline,  and  an 
increase  in  the  alkalinity  of  the  fluids  makes  the  calcium  salts 
decidedly  less  soluble.  Presumably,  under  normal  conditions, 
the  amount  of  calcium  in  the  blood  is  too  slight  to  be  thrown 
down  in  this  way,  but  when  oversaturated  because  of  the  calcium 
absorption  in  the  skeleton,  precipitation  occurs  in  the  parts  of 
the  body  where  the  alkalinity  of  the  blood  or  tissue  fluids  is 
greatest.  A  number  of  cases  similar  to  the  metastatic  form  as 
to  location  and  nature  of  the  deposits  have  been  observed  un- 
accompanied by  any  bone  absorption,  which  complicates  the 
matter  decidedly,  and  some  writers  2  combat  many  of  the  pre- 
vailing ideas  of  metastatic  calcification.  Some  have  attempted 
to  include  the  calcification  of  the  vessels  and  other  tissues  in 
old  age  in  the  metastatic  calcifications,  ascribing  the  origin  of 
the  salts  to  the  senile  absorption  of  bone,  but  it  is  probably 
dependent  rather  upon  the  extensive  hyaline  degeneration  of 
the  connective  tissues  that  occurs  in  the  senile  scleroses. 

CHEMISTRY  OF  THE  PROCESS  OF  CALCIFICATION 

In  analyzing  the  etiological  factors  in  the  production  of  path- 
ological calcification  for  the  purpose  of  determining  the  chem- 
ical changes  that  occur  in  the  process,  we  have  the  following 
facts  upon  which  to  base  the  consideration  : 

(1)  The  calcium  salts  must  come  from  the  blood,  where  they 
are  held  in  solution  or  in  suspension  by  the  proteids,  either  as  the 
carbonate  and  phosphate  themselves,  or  as  calcium-ion-proteid 
compounds,  or  perhaps  both.  This  suspension  or  solution  is  an 
unstable  condition,  possible  only  because  of  the  extremely  small 
proportion  of  calcium  in  the  blood  (about  1  : 10,000),  and,  there- 

1  Virchow's  Arch.,  1855  (8),  103;    review  by  Kockel,  Deut.  Arch.  klin. 
Med.,  1899  (64),  332. 

2  Beer,  Jour.  Path,  and  Bact.,  1903  (9),  225. 


CHEMISTRY  OF  THE  PROCESS  OF  CALCIFICATION  369 

fore,  capable  of  being  overthrown  by  increased  alkalinity  of  the 
blood,  changes  in  the  proteids,  or  changes  in  the  quantity  or 
composition  of  the  calcium  salts. 

(2)  Retrogressive  changes  in  the  tissues  are  a  sine  qua  non. 
Hyaline  degeneration,  the  chemical  nature  of  which  is  not  under- 
stood, is  a  very  favorable  condition,  as  also  is  necrosis  when 
absorption  is  deficient. 

(3)  In  the  areas  that  are  to  become  calcified  the  circulation 
is  very  feeble,  the  blood  plasma  seeping  through  the  tissue  as 
through  any  dead  foreign  substance  of  similar  structure,  without 
the  presence  of  red  corpuscles  to  permit  of  oxidative  changes. 

We  may,  therefore,  imagine  that  the  deposition  of  calcium 
salts  in  such  areas  of  tissue  degeneration  depends  upon  any  one 
of  the  following  conditions  : 

(1)  Increased  alkalinity  in  the  degenerating  tissues,  causing 
precipitation  of  the  inorganic  salts  in  the  fluids  seeping  slowly 
through  them. 

(2)  Utilization  of  the  proteid  of  the  fluids  by  the  starved 
tissues  so  completely,  because  of  its  slow  passage  through  them, 
that  the  calcium  cannot  be  held  longer  in  solution. 

(3)  The  formation  within  the  degenerated  area  of  a  substance 
or  substances  having  a  special  affinity  for  calcium. 

(4)  Production  of  a  physical  condition  favoring  the  absorp- 
tion of  salts,  the  least  soluble  salts  accumulating  in  excess. 

The  first  two  ideas  have  little  indeed  to  support  them,  and 
are  mentioned  chiefly  because  they  have  been  advanced  in  the 
past  by  certain  writers.  The  possibility  of  the  formation  of 
calcium-binding  substances  within  the  degenerated  area  has 
always  seemed  the  most  attractive,  and  has  received  the  most 
attention  by  investigators.  Of  the  special  substances  that 
might  be  present  in  such  areas  that  would  have  a  high  affinity 
for  calcium,  phosphoric  acid  usually  receives  first  consideration, 
since  it  is  as  phosphate  that  most  of  the  calcium  is  bound,  and 
also  since  the  possible  sources  of  phosphoric  acid  in  decomposed 
nucleoproteids  and  lecithin  are  so  obvious.  Less  considered  in 
the  past,  fatty  acids  offer  another  possibility,  especially  in  view 
of  the  fatty  degeneration  that  so  frequently  precedes  calcifica- 
tion. Proteids  might  also  be  formed  that  would  combine  cal- 
cium, especially  deutero-albumose,  which  Croftan :  states  has  a 
high  degree  of  affinity  for  calcium,  and  which  would  be  present 
in  areas  undergoing  autolysis. 

1  Jour,  of  Tuberculosis,  1903  (5),  22. 


370   CALCIFICATION,    CONCRETIONS,  AND  INCRUSTATIONS 

Formation  of  Calcium  Soaps. — In  favor  of  the  possi- 
bility that  the  calcium  is  first  bound  as  soaps  are  the  following 
facts  :  Calcification  occurs  chiefly  in  places  where  fatty  degen- 
eration has  occurred,  such  as  tubercles,  atheromatous  vessels, 
etc.  In  fat  necrosis  fatty  acids  are  formed,  which  soon  com- 
bine with  calcium  to  form  calcium  soaps.  Virchow  observed 
calcification  in  the  form  of  soaps  in  a  lipoma,  and  Jaeckle 1 
found  that  a  calcifying  lipoma  contained  29.5  per  cent,  of  it& 
calcium  in  the  form  of  calcium  soaps.  Klotz 2  obtained  staining 
reactions  in  calcifying  tissues  that  suggested  the  presence  of 
soaps,  which  he  also  extracted  by  solvents,  and  he  strongly 
urges,  as  the  first  step  in  the  formation  of  pathological  calcified 
masses,  that  the  calcium  is  first  laid  down  as  soaps,  afterward 
undergoing  a  transformation  into  the  less  soluble  phosphate  and 
carbonate.  Fischler  and  Gross3  also  obtained  microchemical 
reactions  for  soaps  in  the  margins  of  infarcts  and  in  atheroma- 
tous areas,  but  not  in  caseous  areas  ;  they  therefore  consider 
that  calcium-soap  formation  is  an  important  step  in  the  process 
of  pathological  calcification,  but  that  it  is  not  essential. 

On  the  other  hand,  Wells,4  studying  large  quantities  of 
material  chemically,  found  but  most  minute  traces  of  calcium 
soaps  in  calcifying  matter,  even  in  the  earliest  stages,  and  also 
very  small  amounts  of  other  soaps  or  fatty  acids,  and,  therefore, 
questions  the  occurrence  of  calcium  soaps  as  an  essential  step 
in  calcification,  although  not  doubting  that  under  certain  condi- 
tions (e.  g.,  calcifying  lipomas,  fat  necrosis)  this  may  occur.  In 
calcification  at  all  stages  the  proportion  of  calcium  carbonate 
and  phosphate  was  found  quite  constant,  and  exactly  the  same 
as  in  normal  bone ;  namely,  in  the  proportion  expressed  by  the 
formula  3(Ca3(PO4)2).CaCO3,  which  Hoppe-Seyler  advanced  to- 
express  the  composition  of  the  salts  of  bone.  Hence  it  seems 
probable  that  there  are  no  essential  differences  between  the  pro- 
cesses of  ossification  and  pathological  calcification,  and  there 
seems  to  be  as  yet  no  reason  for  assuming  that  in  the  former 
calcium  soaps  constitute  an  essential  step  in  the  process. 

Phosphoric  Acid  in  Calcification. — It  has  generally 
been  assumed  that  in  normal  ossification  the  calcium  is  combined 
by  phosphoric  acid,  which  probably  is  derived  from  the  cartilage 
cells,  possibly  through  autolysis  of  the  nucleoproteids  or  some 
similar  process.  Grandis  and  Mainini,5  by  using  microchemical 

1  Zeit.  physiol.  Chem.,  1902  (36),  53. 

2  Jour.  Exper.  Med.,  1905  (7),  633 ;  1906  (8),  322. 

3  Ziegler's  Beitr.,  1905  (7th  suppl.),  339. 

4  Loc.  cit. 

5  Arch,  per  la  sci.  Med.  Torino,  1900  (24),  67. 


OSTEOMALACIA  371 

methods,  thought  that  they  found  evidence  that  the  phosphorus 
of  ossifying  cartilage  is  converted  from  an  organic  combination 
into  an  inorganic  form  (P2O5),  which  then  takes  up  calcium  from 
the  blood.  The  methods  used  have  been  questioned,  and  Pac- 
chioni,1  from  his  studies,  was  inclined  to  the  opinion  that  the 
calcium  entered  the  cartilage  already  combined  as  phosphate. 
Wells  implanted  various  tissues  that  had  been  killed  and  steril- 
ized by  boiling  into  the  abdominal  cavity  of  rabbits,  and  found 
that  tissues  rich  in  nucleoproteids  showed  no  tendency  to  take 
up  calcium  in  greater  amounts  than  did  tissues  poor  in  nucleo- 
proteid,  which  result  speaks  against  the  idea  that  phosphoric 
acid  derived  from  nucleic  acid  combines  the  calcium.  On  the 
other  hand,  implanted  cartilage  soon  became  thoroughly  impreg- 
nated with  calcium  salts,  which  seemed  to  be  deposited  in  the 
same  proportion  as  to  carbonate  and  phosphate  as  in  bone. 

Physical  Absorption  of  Calcium  Salts. — As  there  could 
be  no  question  of  "  vital  activity  "  on  the  part  of  this  boiled  car- 
tilage, it  seems  most  probable  that  there  exists  in  cartilage  a 
specific  absorption  affinity  for  calcium  salts,  similar  to  the  absorp- 
tion affinity  that  Hofmeister 2  observed  exhibited  by  other  organic 
colloids  (gelatin  disks)  toward  various  crystalline  substances  in 
solution.  Pfaundler  has  also  demonstrated  that  cartilage  in  the 
test-tube  has  a  specific  absorption  affinity  for  calcium.  It  is 
doubtful  if  ossification  can  be  explained  in  this  simple  manner, 
however,  for  on  this  basis  we  should  expect  the  calcium  to  be 
easily  washed  out  of  the  bones,  and  an  increase  in  calcium 
should  lead  to  increased  ossification.  Furthermore,  it  does  not 
account  for  the  remarkable  specific  affinity  of  cartilage  for  cal- 
cium salts. 

OSTEOMALACIA  3 

In  this  condition  the  quantity  of  inorganic  salts  in  the 
bone  is  greatly  decreased,  while,  at  the  same  time,  their  place  is 
taken  in  part  by  new-formed  osteoid  tissue ;  as  a  result,  the 
proportion  of  the  weight  of  the  bone  formed  by  inorganic  salts 
is  reduced  to  as  low  as  20  to  40  per  cent.,  instead  of  being  from 
56  to  60  per  cent.,  as  in  normal  bone.4  This  suggests  that  the 
cause  of  the  disease  may  be  a  solution  of  the  lime  salts  by  some 
acid,  in  support  of  which  Schmidt  has  reported  the  finding  of 
lactic  acid  in  the  altered  substance  of  the  bones  in  osteomalacia, 

1  Jahrb.  f.  Kinderheilk.,  1902  (56),  327. 

2  Arch,  exper.  Path.  u.  Pharm.,  1891  (28),  210. 

3  See  also   review  in  Albu  and   Neuberg's  "  Mineralstoffwechsel,"  Berlin, 
1906,  pp.  124-127. 

4  Full  figures  given  by  Senator,  Ziemssen's  Handbuch,  1879  (13),  236. 


372   CALCIFICATION,    CONCRETIONS,   AND  INCRUSTATIONS 

while  other  observers  have  stated  that  in  osteomalacia  the 
alkalinity  of  the  blood  is  reduced,  and  that  lactic  acid  appears 
in  the  urine.  All  the  above  statements  are  of  questionable 
value,  and  it  is  improbable  that  there  is  any  such  degree  of 
acidity  or,  better,  lack  of  alkalinity,  in  the  blood  or  fluids  in  the 
bones  as  to  dissolve  out  the  inorganic  salts.  Levy  l  found  that 
in  osteomalacia  the  proportion  of  calcium  carbonate  and  phos- 
phate in  the  bones  remains  constant,  as  also  does  the  proportion 
of  calcium  and  phosphoric  acid  ;  if  the  decalcification  occurred 
through  solution  by  lactic  or  other  acids,  the  carbonate  should 
be  decomposed  first,  whereas  the  lime  salts  seem  to  be  taken 
out  as  molecules  of  calcium  carbonate-phosphate ;  i.  e.,  in  the 
same  proportion  as  they  exist  in  the  bone.  On  the  other  hand, 
it  has  been  found  in  Pawlow's  laboratory  that  dogs  kept  for 
long  periods  after  a  pancreatic  fistula  has  been  established, 
develop  a  condition  resembling  osteomalacia,2  which  would 
seem  most  reasonably  explained  as  due  to  the  constant  loss 
of  alkali  in  the  pancreatic  juice.  Histologically,  absorption 
seems  to  depend  largely  upon  a  direct  eating  out  of  bone 
tissue,  both  organic  and  inorganic  substance,  by  osteoclasts 
(Cohuheim),  followed  by  a  formation  of  an  uncalcified  osteoid 
tissue.  (Senile  osteoporosis  differs  chiefly  in  that  no  new  osteoid 
tissue  is  formed.)  According  to  Schmidt  and  to  Langendorif 
and  Mommsen,  this  new-formed  osteoid  tissue  yields  no  gelatin, 
and,  therefore,  is  quite  different  from  normal  osteoid  tissue.  It 
is  not  established,  however,  that  this  alteration  is  a  constant 
occurrence  in  osteomalacia.  In  many  cases  of  osteomalacia  the 
rapid  rate  of  progress  of  the  disease  indicates  that  it  is  not 
simply  a  normal  absorption  of  lime  salts  with  defective  replace- 
ment, but  that  an  excessive  absorption  must  occur  (Pommer 3). 
Chabrie 4  found  that  much  of  the  calcium  absorbed  is  replaced 
by  magnesium,  so  that  the  latter  may  be  in  excess  of  the  former ; 
he  found  in  one  case  22.2  per  cent,  of  CaO  and  26.9  per  cent, 
of  MgO.  Malcolm 5  has  found  that  ingestion  of  considerable 
quantities  of  magnesium  salts  causes  loss  of  calcium  in  adult 
animals,  and  hinders  its  deposition  in  growing  animals,  but 
there  is  no  evidence  to  connect  this  fact  with  the  increased 
magnesium  in  the  bones  in  osteomalacia. 

Studies  of  metabolism  in  osteomalacia  have  shown  a  loss  of 


1  Zeit.  physiol.  Chera.,  1894  (19),  239. 

2  Personal  communication  from  Dr.  Boris  Babkin. 

3  Vierordt,  Nothnagel's  System,  vol.  7,  part  ii,  p.  124. 

4  Les  phenomenes  chim.  de  1' ossification,  Paris,  1895. 

5  Jour,  of  Physiol.,  1905  (32),  182. 


RICKETS 


373 


calcium  by  the  body,  as  shown  by  the  following  table  given  by 
Goldthwait  et  al.  : l 


Limbeck. 

Neumann. 

Goldthwait. 

1  773 

3859 

CaO  in  feces 

3834 

1  800 

5  607 

11  65 

566 

Total  in  food  

2.965 

11.26 

4.56 

Loss  of  CaO    

2.965 

0.39 

1.10 

These  authors  also  found  a  considerable  retention  of  nitrogen 
and  sulphur,  which  they  suggest  may  be  retained  in  the  new- 
formed  osteoid  tissue  ;  magnesium  is  also  retained,  probably 
being  substituted  for  calcium  in  the  bones. 

Castration  of  women  with  osteomalacia  has  been  frequently, 
but  not  always,  followed  by  improvement  or  recovery,  and 
Neumann,  and  also  Goldthwait,  have  found  that  in  these  cases 
the  calcium  loss  is  replaced  by  a  marked  calcium  retention  after 
the  operation.  What  the  relation  of  the  ovaries  to  calcium 
metabolism  or  to  osteomalacia  may  be  has  not  yet  been  ascer- 
tained. Scharfe2  and  Bulins3  both  state  that  there  are  no 
characteristic  or  constant  structural  alterations  in  the  ovaries  in 
osteomalacia.  McCrudden  4  found  that  the  improvement  in 
calcium  metabolism  observed  after  castration  may  be  but  tem- 
porary, and  therefore  believes  that  the  primary  cause  of  the 
disease  does  not  lie  in  the  ovaries. 


RICKETS  5 

As  with  osteomalacia,  chemical  studies  of  the  bones  in  rickets 
have  thrown  little  light  upon  the  etiology  or  pathogenesis  of 
this  condition.  As  the  following  table  (taken  from  Vierordt6) 
shows,  there  is  a  marked  deficiency  in  the  proportion  of  inorganic 
salts  in  the  bones  in  rickets.  The  proportion  of  the  different 
salts,  seems  to  be  quite  the  same  as  in  normal  bone. 

1  Goldthwait,  Painter,  Osgood  and  McCrudden,  Amer.  Jour.  PhysioL,  1905 
(14),  389. 

2  Cent,  f.  Gyn.,  1900  (24),  1216. 

3  Beitr.  z.  Geb.  u.  Gyn.,  vol.  1. 

4  Amer.  Jour,  of  Physiol.,  1906  (17),  211. 

5  Complete  literature  and  full  discussion  by  Pfaundler,  Jahr.  f.  Kinderheilk., 
1904  (60),  123 ;   also  see  Albu  and   Neuberg,  "  Mineralstoffwechsel,"  Berlin, 
1906,  pp.  119-124. 

6  Nothnagel's  System,  vol.  7,  part  ii,  p.  21. 


374   CALCIFICATION,    CONCRETIONS,   AND  INCRUSTATIONS 


Normal  bone 

of  a  two 
months'  old 

Rachitic  bones. 

child. 

Tibia. 

Ulna. 

Femur. 

Tibia. 

Humerus. 

Ribs. 

Vertebrae. 

Inorganic  matter  .... 

65.32 

64.07 

20.60 

33.64 

18.88 

37.19 

32.29 

Organic  substance    .   .   . 

34.68 

35.93 

79.40 

66.36 

81.12 

62.91 

67.71 

Calcium  phosphate  .   .   . 
Magnesium  phosphate    . 
Calcium  carbonate   .  .   . 

57.54 
1.03 
6.02 

56.35 
1.00 
6.07 

14.78 
0.80 
3.00 

26.94  ) 
0.81  f 
4.88 

15.60 
2.66 

Soluble  salts     

0.73 

1.65 

1.02 

1.08 

0.62 

Collagen  (or  ossein)  .  .  . 
Fat    

33.86 
0.82 

34.92 
1.01 

72.20 
7.20 

60.14) 
6.22) 

81.22 

As  an  essential  difference  from  osteomalacia  is  the  fact  that 
in  rickets  there  is  a  failure  on  the  part  of  the  osteoid  tissues  to 
calcify,  whereas  in  osteomalacia  absorption  of  calcified  tissue 
takes  place  with  subsequent  substitution  by  osteoid  tissue. 
Furthermore,  in  rickets  the  deficiency  in  calcium  is  only  present 
in  the  bones,  whereas  in  osteomalacia  the  soft  tissues  are  also 
poor  in  lime  salts. 

None  of  the  various  hypotheses  as  yet  advanced  to  explain 
this  defective  ossification  has  satisfactorily  explained  all  the 
observed  facts.  That  a  deficiency  of  calcium  in  the  food  is  the 
cause  of  rickets  is  a  most  natural  assumption,  but  it  has  not 
been  proved  that  this  is  the  case.  Young  animals  fed  on  cal- 
cium-poor foods  show,  naturally  enough,  defective  develop- 
ment of  the  bone,  but  this  differs  essentially  from  rickets  in  that 
the  bone  formed  is  defective  chiefly  in  amount  rather  than  in 
quality  (Stoltzner).  Furthermore,  such  "  pseudo-rachitic  bone  " 
possesses  a  marked  affinity  for  calcium  salts,  and  takes  them 
up  as  soon  as  they  are  supplied  (Pfaundler).  Bland-Sutton, 
Cheadle,1  and  others  consider  that  a  deficiency  of  fat  and  pro- 
teid  in  the  diet  is  the  essential  cause.  Zweifel  and  others  have 
advanced  the  idea  that  there  is  a  defective  absorption  of  calcium 
from  the  foods,  depending  upon  a  lack  of  HC1  in  the  gastric 
juice ;  this  hypothesis  seems  to  be  poorly  founded.  In  view 
of  the  fact  that  rickets  is  not  solely  a  disease  of  bone  tissue,  but 
that  all  the  various  important  viscera,  as  well  as  the  muscles  and 
tendons,  show  pathological  changes,  it  seems  most  reasonable 
that  rickets  should  be  looked  upon  as  a  constitutional  disease,  in 
which  the  bone  changes  are  prominent  chiefly  because  the  disease 
occurs  at  a  time  when  the  bone  tissue  is  most  actively  forming 
and  when  the  other  organs  are  relatively  quite  completely 
1  Allbutt's  System,  1897  (3),  108. 


CONCRETIONS  375 

developed.  Stoltzner,1  finding  evidence  that  rickets  does  not 
depend  upon  either  lack  of  calcium  in  the  food  or  deficient  ab- 
sorption of  calcium,  and  that  the  blood  in  rickets  is  of  normal 
alkalinity,  looks  upon  the  failure  of  calcification  as  depending 
upon  an  abnormality  in  the  calcified  bone  tissue  itself.  He 
finds  evidence  of  a  preliminary  alteration  in  normal  osteoid 
tissue  which  prepares  it  to  take  the  salts  out  of  the  blood,  and 
Pfaundler 2  supports  this  view,  suggesting  that  this  preparatory 
ohange  in  the  osteoid  tissue  may  depend  upon  autolysis,  which 
is  perhaps  deficient  in  rickets.3 

CONCRETIONS 

All  pathological  concretions  appear  to  be  laid  down  according 
to  a  definite  law.  There  must  first  be  a  nucleus  of  some  sub- 
stance different  from  the  substance  that  is  to  be  deposited,  and 
which  is  most  frequently  a  mass  of  desquamated  cells,  but  may 
consist  of  clumped  bacteria,  masses  of  mucus,  precipitated  pro- 
teids,  or  a  foreign  body  of  almost  any  sort.  Upon  this  nucleus 
substances  crystallize  out  of  solution,  much  as  cane-sugar  crys- 
tallizes on  a  string  to  form  rock  candy,  but  with  the  impor- 
tant exception  that  among  the  crystals  is  usually  deposited 
more  or  less  mucin  or  other  organic  substance,  which  forms 
a  framework  in  which  the  crystals  lie,  and  which  remains,  if  the 
crystals  are  dissolved  out,  as  a  more  or  less  perfect  skeleton 
of  the  concretion.  In  no  case  would  the  concretion  form  were 
it  not  that  the  solution  is  overcharged  with  some  substance,  but 
not  infrequently  it  is  the  presence  of  the  nucleus  that  leads  to 
the  precipitation  of  the  substance ;  i.  e.,  the  nucleus  may  play 
either  a  primary  or  a  secondary  role.  With  few  exceptions,  the 
dissolved  substance  is  deposited  in  crystalline  form,  although 
the  crystalline  structure  may  in  time  partly  disappear  through 
condensation  or  through  filling  of  the  interstices  with  some 
other  material.  Even  so  structureless  a  substance  as  amyloid 
may,  when  forming  concretions,  appear  in  a  crystalline  form 
(Ophiils).  The  structure  of  a  concretion  depends  upon  two 
factors :  The  crystals  tend  to  be  deposited  at  right  angles  to 
the  surface,  and  thus  give  a  radiating  structure ;  but  the  rate  of 
deposition  is  usually  irregular,  and  during  the  periods  of  quies- 
cence the  surface  tends  to  become  covered  with  mucin  or  other 
organic  substances,  hence  we  also  get  a  concentric,  laminated 

1  Jahrb.  f.  Kinderheilk.,  1899  (50),  268. 

2  Loc.  eit. 

3  See  also  Nathan,  Med.  News,  1904  (84),  391. 


376   CALCIFICATION,   CONCRETIONS,  AND  INCRUSTATIONS 

structure.  Frequently  both  of  these  lines  of  formation  are 
easily  discerned,  but  either  one  or  the  other  may  become 
obscured. 

The  chemistry  of  concretions  is,  therefore,  a  relatively  simple 
matter,  and  it  remains  merely  to  give  the  chief  facts  concerning 
the  formation  and  composition  of  the  different  varieties. 

BILIARY  CALCULI 

As  may  be  judged  from  the  above  statements,  concretions  are 
never  composed  of  one  substance  in  a  pure  form,  but  usually  con- 
sist of  a  mixture  of  the  constituents  of  the  fluid  in  which  they 
are  developed.  This  is  particularly  true  of  gall-stones,  which 
contain  in  greater  or  less  quantities  several  or  all  of  the  constitu- 
ents of  the  bile.  While  cholesterin  forms  the  greater  part  of 
nearly  all  biliary  concretions,  and  is  present  in  greater  or  less 
amounts  in  all,  calcium  salts  of  the  bile-pigments  are  always 
present ;  usually  inorganic  salts  of  calcium  (carbonate  and  phos- 
phate) are  also  present,  as  well  as  small  amounts  of  fats,  soaps, 
lecithin,  mucus,  and  other  products,  and  occasionally  traces  of 
copper,  iron,  and  manganese.1  The  quantity  of  bile  salts,  the 
chief  constituent  of  the  bile,  is  usually  extremely  minute,  appar- 
ently only  so  much  as  may  percolate  into  the  crevices  of  the 
concretion.  However  many  stones  there  may  be  in  a  gall- 
bladder, they  usually  are  all  of  approximately  the  same  com- 
position and  structure. 

In  gall-stones  from  the  domestic  animals  the  proportion  of 
inorganic  salts  is  usually  much  higher  than  it  is  in  man. 

Naunyn  has  classified  gall-stones  according  to  their  composi- 
tion, as  follows : 

1.  "  Pure"  Cholesterin2  Stones. — The  purity  is  only  rela- 
tive, since  even  the  purest  always  contain  some  pigment  as  well 
as  a  stroma  and  a  nucleus ;  but  the  amount  of  cholesterin  may 
reach   98   per  cent.,  and   is  usually   over  90  per  cent.     Crys- 
talline structure  is  usually  well  marked,  while  stratification  is 
slight.     The  color  varies  from  nearly  pure  white  to  yellow,  or 
even  brown  on  the  surface. 

2.  Laminated  Cholesterin  Stones. — These  consist  of  about 
75-90  per  cent,  of  cholesterin,  and  differ  from  the  preceding 
form  in  containing  more  pigment,  which  is  deposited  in  layers 
alternating  with  the  white  layers  of  cholesterin.     The  pigment 

^all-stones  have  been  found  enclosing  droplets  of  mercury.  (Naunyn, 
Frerichs.) 

2  Concerning  composition  and  occurrence  of  cholesterin,  see  pages  28  and 
346. 


BILIARY   CALCULI  377 

here,  as  in  all  other  gall-stones,  consists  always  of  the  calcium 
salts  of  the  pigments — not  of  pure  bilirubin  and  biliverdin 
themselves.  Considerable  calcium  carbonate  is  also  usually- 
present,  particularly  in  the  green  layers  of  biliverdin  cal- 
cium. 

3.  Common  Gall-bladder  Stones. — The  composition  of  this 
form  is  but  little  different  from  the  above,  the  chief  difference 
being  in  the  structure.      They  present  externally  a  firmer  crust, 
usually  distinctly  laminated  ;  in  the  center  is  a  softer  pigmented 
nucleus   which   frequently  shows   a    central    cavity  containing 
fluid.     Such  calculi  are  not  distinctly   crystalline  in  structure, 
and  are  small,  seldom  larger  than  a  cherry. 

4.  Mixed  Bilirubin-calcium  Calculi. — These  generally  occur 
singly,  but  sometimes  in  groups  of  three  or  four,  and  are  of 
large  size.     Although  the  chief  constituent  is  bilirubin-calcium, 
there  is   always    much   cholesterin,   often    over    25    per  cent. 
Copper  and  traces  of  iron  may  also  be  present.     Their  structure 
is  laminated,  with  sometimes  a  crystalline  cholesterin  nucleus. 

5.  "  Pure  "  Bilirubin-calcium  Calculi. — In  addition  to  the 
chief  constituent,  biliverdm-ealcium,  bilifuscin,  and  bilihumin  l 
are  practically  always  present.     Bilihumin  is  at  times  the  chief 
ingredient,  and  may  form  over  half  of  the  substance  ;  bilicyanin 
is  rarely  present.     There  is  always  some  cholesterin,  but  some- 
times only  traces.     These  calculi  are  small,  from  the  size  of  a 
grain  of  sand  to  that  of  a  pea,  and  they  occur  in  two  distinct 
forms.     One  form  is  of  wax -like  consistence  ;  the  other  is  harder, 
steel-gray  or  black  in  color,  with  a  metallic  luster.      Pure  bili- 
rubin and  biliverdin,  not  combined  with  calcium,  are  practically 
never  present  in  concretions. 

6.  Rarer  Forms. — (a)  Amorphous    and  incompletely  crystal- 
line cholesterin  gravel.     Cholesterin   externally  giving  them    a 
pearly  luster ;  pigment  in  the  center. 

(6)  Calcareous  Stones. — Consist  chiefly  of  a  mixture  of  cal- 
cium carbonate  and  bilirubin-calcium.  Calcium  carbonate  may 
occur  either  as  a  superficial  crust,  or  as  small  masses  within  an 
ordinary  calculus  ;  calcium  sulphate  and  phosphate  occur  rarely 
in  traces.  Stones  consisting  mainly  of  calcium  carbonate  are 
extremely  rare  in  man,  but  more  frequent  in  cattle  and  other 

1  Biliverdin  differs  from  bilirubin  in  containing  one  more  atom  of  oxygen  in 
the  molecule,  and  it  is  easily  formed  from  bilirubin — even  exposure  to  air  will 
slowly  bring  about  the  oxidation.  Bilifuscin  is  a  still  more  oxidized  deriva- 
tive —so  much  so  that  it  does  not  give  Gmelin's  reaction  (with  HNO3  +  HNO2) 
for  bile-pigments.  Bilihumin  represents  the  most  oxidized  of  these  products, 
is  brown  in  color,  and  is  the  chief  constituent  of  the  residue  left  after  treating 
gall-stones  with  ether,  alcohol,  and  chloroform  to  dissolve  out  the  cholesterin. 


378   CALCIFICATION,   CONCRETIONS,  AND  INCRUSTATIONS 

herbivora,  in  which  all  forms  of  concretions  contain  much 
calcium,  either  combined  with  pigment  or  as  carbonate  and 
phosphate. 

(c)  Concretions  with  included  bodies,  and  conglomerate  stones. 

(d)  Casts  of  Bile-ducts. — Occur  particularly  in  cattle,  and 
consist  chiefly  of  bilirubin-calcium.     Rarely   and   imperfectly 
formed  in  man. 

Formation  of  Gall-stones. — We  owe  our  present 
understanding  of  the  chemistry  and  pathology  of  the  formation 
of  gall-stones  chiefly  to  Naunyn  l  and  his  pupils.  Former 
observers,  having  learned  that  bile  normally  contains  cholesterin 
(Hammarsten  found  from  0.06-0. 16  per  cent,  in  human  bile), 
sought  the  cause  of  gall-stones  in  either  an  increased  elimina- 
tion of  cholesterin  by  the  liver,  or  a  decrease  in  the  power  of 
the  bile  to  hold  the  cholesterin  in  solution.  Thus  Frerichs, 
finding  that  the  presence  of  large  amounts  of  bile  salts  and  an 
alkaline  reaction  favored  the  solution  of  cholesterin,  imagined 
that  a  diminution  of  either  bile  salts  or  alkalinity  led  to  the 
precipitation  of  the  cholesterin.  Naunyn  and  his  pupils,  how- 
ever, demonstrated  that  the  amount  of  cholesterin  present  in 
the  bile  does  not  depend  upon  the  amount  taken  in  the  food  or 
the  amount  present  in  the  blood ;  and  that  it  did  not  vary  in 
disease,  except  when  gall-stones  were  present.  They  concluded 
that  the  cholesterin  of  the  bile  is  neither  a  product  of  general 
metabolism  nor  a  specific  secretion-product  of  the  liver.  Find- 
ing that  pus  and  the  secretions  from  inflamed  mucous  membranes 
(bronchitis)  contained  as  much  cholesterin  as  did  normal  bile, 
and  often  more,  they  concluded  that  the  chief  source  of  choles- 
terin in  gall-stone  formation  was  from  the  degenerating  and 
desquamated  epithelial  cells  of  the  gall-bladder  and  bile  tracts. 
This  idea  was  supported  by  the  large  amount  of  cholesterin 
found  in  the  contents  of  gall-bladders  shut  off  from  the  com- 
mon duct,  and  by  the  formation  of  gall-stones  in  such  isolated 
gall-bladders.  Further  evidence  has  since  been  brought  for- 
ward in  favor  of  this  same  view,2  until  it  is  now  generally 
accepted  as  correct.  It  is  now  believed  that  the  ordinary  steps 
in  the  formation  of  a  cholesterin  concretion  are  as  follows  : 
Some  injury  to  the  mucous  membrane  of  the  bile  tracts  is  the 

1  An  English  translation  of  this  classic  work,  by  A.  E.  Garrod,  has  been 
published  by  the  Sydenham  Society,  1896,  vol.  158. 

2  Thus  Wakeman  (quoted  by  Herter,  Trans.  Congress  Amer.  Physicians, 
1903  (6),  158;  excellent  resume)  was  able  to  cause  an  increase  in  the  choles- 
terin of  the  bile  in  the  gall-bladder  of  dogs  by  injecting  into  it  HgCl2,  phenol, 
or  ricin.  At  first  the  cholesterin  seems  to  be  contained  largely  in  the  degenerat- 
ing desquamated  cells. 


BILIARY  CALCULI  379 

starting-point ;  this  injury  is  usually  produced  by  infection,  the 
colon  and  typhoid  bacilli  being  the  most  common  organisms  in 
this  process.1  It  is  probable  that  injury  alone  is  not  sufficient 
to  cause  gall-stone  formation,  but  infection  is  essential  (Miyaka2). 
Through  the  degeneration  of  the  epithelial  cells  an  excess  of 
cholesterin  is  formed,  while  at  the  same  time  the  desquamated 
cells  and  clumped  bacteria  offer  suitable  nuclei  upon  which  the 
cholesterin  begins  to  crystallize  out.  Apparently  after  the  cal- 
culi have  reached  a  certain  size  they  cause  sufficient  mechanical 
injury  to  keep  up  the  cell  degeneration  and  cholesterin  forma- 
tion, even  after  the  infection  has  subsided.  A  certain  amount 
of  infection  and  inflammation  is  a  favoring  condition,  however, 
for  Harley  and  Barratt3  found  that  fragments  of  cholesterin 
calculi  introduced  aseptically  into  the  gall-bladders  of  dogs 
were  slowly  dissolved  and  disappeared,  but  this  was  prevented 
by  infecting  the  gall-bladder  with  I>.  coli.  According  to 
Naunyn's  investigations,  it  is  not  an  alteration  in  the  composi- 
tion of  the  bile,  as  formed  in  the  liver,  which  causes  the  precipi- 
tation of  cholesterin,  but  rather  the  presence  of  the  nidus,  and 
the  production  of  large  quantities  of  cholesterin  in  immediate 
proximity  to  this  nidus,  that  determines  the  formation  of  a  con- 
cretion. In  case  the  bile  stagnates  in  the  gall-bladder,  the 
cholesterin  that  is  being  constantly  formed  by  the  normal  dis- 
integration of  surface  epithelium  accumulates,  until,  even  without 
infection,  there  forms  a  sediment  of  soft  yellowish  and  brown- 
ish masses,  consisting  chiefly  of  cholesterin  and  bilirubin-calcium. 
From  this  material  calculi  may  eventually  form,  and  by  their 
irritation  lead  to  further  formation  of  cholesterin  and  increased 
growth.  But  bacteriological  studies  indicate  that  generally  an 
infectious  influence  is  present  in  cholelithiasis,  and  bacilli  may 
be  found  alive  in  gall-stones  for  remarkably  long  periods. 

It  was  formerly  supposed  that  the  calcium-pigment  concre- 
tions were  produced  by  the  presence  of  excessive  calcium  in  the 
bile,  derived  particularly  from  lime-laden  drinking-water,  but 
it  has  been  demonstrated  that  increase  of  calcium  in  the  food 
does  not  cause  an  increase  in  the  amount  in  the  bile.  Further- 
more, on  concentrating  bile,  which  contains  both  bilirubin  and 
calcium,  the  free  bilirubin  separates  out  and  not  the  calcium 

^ee  Cashing  (Johns  Hopkins  Hosp.  Bull.,  1899  (10),  166),  who  produced 
gall-stones  experimentally  by  injecting  typhoid  bacilli  into  the  circulation  after 
injuring  the  gall-bladder.  Literature  on  the  relation  of  bacteria  to  gall-stones 
given  by  Cushing ;  also  by  Pratt,  Amer.  Jour.  Med.  Sci.,  1901  (122),  584;  by 
Bierring,  Jour.  Amer.  Med.  Assoc.,  1904  (43),  1099;  and  by  Herter  (loc.  etV.). 

2  Mitt.  a.  d.  Grenzgeb.  Med.  u.  Chir.,  1900  (6),  479. 

3  Jour,  of  Physiol.,  1903  (29),  341. 


380   CALCIFICATION,    CONCRETIONS,   AND  INCRUSTATIONS 

compound  of  bilirubin ;  and  also  Naunyn  found  that  the  bile 
salts  prevent  precipitation  of  calcium- bilirubin,  even  when 
calcium  salts  are  added  in  considerable  amounts.  Apparently 
it  is  the  presence  of  proteid  substances  that  leads  to  the  precipi- 
tation of  this  compound  from  bile,  and  hence  the  formation  of 
pigment  calculi  is  also  favored  or  initiated  by  inflammation  of 
the  bile  tracts,  particularly  as  most  of  the  calcium  salts  seem  to 
come  from  the  mucous  membrane ; l  later,  as  we  have  seen, 
these  pigment  concretions  often  become  covered  with  cholesterin 
derived  from  the  injured  epithelium,  and  the  common  mixed 
calculi  are  then  formed.  In  view  of  the  fact  that  much  of  the 
pigment  in  these  calculi  is  composed  of  the  oxidation  products 
of  bilirubin,  especially  bttihumin,  it  is  possible  that  oxidation 
processes  in  the  stagnating  bile  are  important  causes  of  the 
precipitation  ;  Naunyn  suggests  that  bacteria  may  be  the  cause 
of  the  oxidation.  Pigment  calculi  are  particularly  important 
as  the  starting-point  of  the  larger  mixed  calculi.  It  is  possible, 
Naunyn  believes,  for  the  pigment  to  be  later  gradually  replaced 
by  cholesterin. 

URINARY  CALCULI  ' 

These  differ  from  the  bile  concretions  in  two  important  re- 
spects :  first,  their  constituents  are  derived  from  the  secretion 
of  the  kidney  rather  than  from  the  walls  of  the  excretory  pas- 
sages, and  they  are  usually  deposited  on  account  of  an  over- 
saturation  of  the  urine,  or  on  account  of  a  change  in  compo- 
sition of  the  urine,  which  renders  them  insoluble.  Second,  the 
composition  of  urinary  calculi  is  usually  less  mixed  than  that 
of  biliary  calculi,  although  seldom,  if  ever,  is  it  pure.  Thus, 
Finsterer  found  but  six  concretions  composed  of  only  one  sub- 
stance, in  a  collection  of  114  calculi.  As  with  the  bile,  the 
chief  constituent  of  the  urine  (urea)  is  so  soluble  that  it  never 
forms  concretions,  but  only  the  less  soluble  minor  constituents 
are  thrown  down.  For  the  formation  of  calculi,  however,  it  is 
not  sufficient  to  have  merely  an  excess  of  a  substance  in  the 
urine,  for  we  may  have  deposition  of  urates,  phosphates,  or  uric 
acid  in  simple  crystalline  form  without  the  formation  of  calculi. 
A  nucleus  of  some  sort  must  be  present  as  well  as  a  binding 
substance,  which  is  often  mucus  derived  from  the  walls  of  the 

1  Baldwin  (quoted  by  Herter,  loc.  cit.)  found  human  cystic  bile  to  contain 
an  average  of  0.072  per  cent,  of  calcium,  the  amount  not  showing  any  constant 
relation  to  the  quantity  of  cholesterin  present.     The  presence  of  calcium  pig- 
ment stones  was  not  associated  with  an  excess  of  calcium  in  the  bile. 

2  General  bibliography  given  by  Finsterer,  Deut.  Zeit.  klin.  Chir.,  1906 
(80),  414. 


URINARY  CALCULI  381 

passages,  although  the  center  of  the  concretion  most  often  con- 
sists of  uric  acid  or  urates.  Infection  does  not  always  play  so 
important  a  part  here  as  it  seems  to  in  the  formation  of  biliary 
calculi  ;  calculi  formed  because  of  changes  in  the  urinary  com- 
position independent  of  infection  are  often  called  "  primary/'  in 
contradistinction  to  those  arising  from  changes  in  composition 
brought  about  by  infection  and  ammoniacal  decomposition. 
Because  of  the  injury  produced  by  a  primary  calculus,  infection 
frequently  results,  and  then  the  primary  calculus  may  become 
the  nucleus  of  a  secondary  calculus  ;  indeed,  on  account  of  the 
change  of  reaction,  the  primary  calculus  may  be  dissolved  out, 
and  its  place  taken  by  the  secondary  deposit  (metamorphosed 
calculi).  In  structure  urinary  calculi  usually  show  both  radi- 
ating and  concentric  lines  of  formation,  and  when  the  chief 
constituents  are  dissolved  away,  an  organic  framework  remains. 
They  are  generally  classified  according  to  their  composition,  as 
follows : 

Uric-acid  Calculi. — Uric  acid  is  but  slightly  soluble,  only 
one  part  dissolving  in  39,480  of  pure  water  at  18°,  and  it  is  even 
less  soluble  in  the  presence  of  acids.  The  presence  of  sodium 
diphosphate  in  the  solution  makes  it  much  more  soluble,  and 
various  organic  bodies  also  favor  its  solution,  among  them 
being  the  urinary  pigments.  As  can  be  seen,  the  maintenance 
of  uric  acid  in  solution  is  by  a  small  margin,  even  in  normal 
conditions  ;  hence  the  mere  cooling  of  the  urine  frequently  suf- 
fices to  cause  an  abundant  deposition  of  uric  acid  combined 
with  pigment,  as  the  familiar  "  brick-dust "  deposit.  The  for- 
mation of  uric-acid  calculi  is,  therefore,  not  only  a  question  of 
the  amount  of  uric  acid  in  the  urine,  but  depends  even  more 
upon  the  amount  of  the  substances  that  hold  it  in  solution,  and 
as  both  these  factors  are  subject  to  wide  variations  under  both 
physiological  and  pathological  conditions,  uric-acid  and  urate 
calculi  are  the  commonest  of  urinary  concretions.  Uric  acid  is 
eliminated  combined  chiefly  with  sodium,  potassium,  and  am- 
monium ;  according  to  some  authors,  as  a  biurate,  according  to 
others,  as  a  quadriurate.  If  the  urine  is  excessively  acid,  it  con- 
tains much  acid  phosphates,  which  withdraw  part  of  the  bases 
from  the  uric  acid,  and  this,  when  free,  crystallizes  out  if  in 
excess.  Hence  the  formation  of  uric-acid  concretions  is  favored 
by  high  acidity  of  the  urine,  by  concentration  of  the  urine,  or 
by  an  increased  elimination  of  the  uric  acid.  The  last  may 
result  from  excessive  nuclein-rich  food,  or  from  excessive  katab- 
olism  of  the  tissue  nucleoproteids  (e.  g.y  leucocytosis  from  in- 
flammatory diseases  or  leukemia),  which  conditions  are  also 


382   CALCIFICATION,   CONCRETIONS,   AND  INCRUSTATIONS 

usually  associated  with  an  increased  urinary  acidity.  (The 
chemistry  of  uric  acid  is  discussed  more  fully  in  the  chapter  on 
"  Gout,"  Chap,  xxi.) 

Uric-acid  calculi  are  formed  chiefly  in  the  pelvis  of  the  kid- 
ney, but  many  pass  into  the  bladder.  They  are  quite  hard, 
and  yellow  or  reddish-yellow  in  color,  because  of  the  presence 
of  urochrome  and  urobilin,  the  former  of  which  seems  to  be 
chemically  combined  and  the  latter  but  physically,  since  it  can 
be  washed  out  with  water.  Urcerythrin  or  uromelanin  (a  de- 
composition product  of  urochrome)  may  also  be  present.  Not 
infrequently  calcium  oxalate  is  present,  sometimes  in  consider- 
able quantities.  Other  urinary  constituents  may  be  present  in 
small  amounts.  In  case  the  calculus  enters  the  urinary  bladder 
it  may  set  up  irritation  leading  to  infection  ;  the  urine  then 
becoming  alkaline,  calcium  and  ammonio-magnesium  phosphate 
will  be  deposited  upon  the  surface,  and  the  uric  acid  will  be 
more  or  less  dissolved  out  and  replaced  by  the  phosphates 
(metamorphosis). 

Urate  calculi  occur  chiefly  in  new-born  or  young  infants, 
and  rarely  in  adults.  In  the  young  they  are  related  to,  and 
may  originate  in,  the  deposits  of  urates  in  the  pyramids  of  the 
kidney  (the  so-called  urate  or  uric-acid  "  infarcts  "),  which  have 
been  supposed  to  result  from  the  decomposition  of  the  nucleo- 
proteids  of  the  nucleated  fetal  red  corpuscles.  (See  "  Uric  Acid," 
Chap,  xxi.)  The  concretions  are  composed  chiefly  of  either 
ammonium  or  sodium  urate,  but  potassium  and  even  calcium 
and  magnesium  urate  may  be  admixed.  Their  genesis  in  the 
young  probably  depends  upon  injury  to  epithelium  by  the  ex- 
cessive urates  of  the  "  infarcts,"  which  affords  a  suitable  nucleus 
for  their  start ;  their  growth  depends  chiefly  upon  the  concen- 
tration of  the  infant's  urine.  In  adults  they  may  arise  second- 
ary to  an  ammoniacal  decomposition  of  the  urine.  Urate 
concretions  are  not  common ;  they  are  generally  rather  soft, 
and  often  much  colored  by  pigments. 

Calcium  oxalate  calculi  are  the  hardest  of  all  concretions 
(except  some  forms  of  the  rare  calcium  carbonate  calculi)  and 
in  frequency  stand  next  to  the  uric-acid  calculi.  Often  they 
show  admixtures  of  urates  or  uric  acid,  which  latter  frequently 
constitutes  the  nucleus,  and  when  urinary  infection  occurs  they 
may  in  turn  serve  as  the  nucleus  to  phosphatic  deposits.  On 
account  of  the  hardness  and  roughness  of  these  stones  they 
frequently  cause  bleeding,  which  may  result  in  their  being  very 
dark  in  color  and  containing  blood-pigment.  They  are  usually 
first  formed  in  the  pelvis  of  the  kidney,  and  arise  chiefly  in 


URINARY  CALCULI  383 

persons  excreting  excessive  quantities  of  oxalic  acid.  Nor- 
mally but  about  0.02-0.05  gram  of  oxalic  acid  is  eliminated 
daily  in  the  urine,  apparently  all  as  calcium  oxalate,  which  is 
kept  in  solution  by  the  acid  phosphates.  The  amount  may  be 
increased  by  certain  foods  rich  in  oxalates,  particularly  rhubarb, 
grapes,  spinach,  etc. ;  also  probably  by  gastric  fermentation.1 
Oxalic  acid  seems  normally  to  be  formed  from  uric  acid,  and 
perhaps  also  from  the  carbohydrate  group  of  proteids,2  and  it 
is  possible  that  abnormally  large  amounts  arise  from  these 
sources  under  pathological  conditions. 

Phosphate  calculi  are  formed  as  a  result  of  decomposition 
of  the  urine,  with  formation  of  ammonia  from  the  urea.  In 
the  ammoniacal  solution  thus  formed  the  magnesium  is  precipi- 
tated as  NH4MgPO4,  the  calcium  as  Ca3(PO4)2,  and  calcium 
oxalate  and  ammonium  urate  are  also  thrown  down,  so  that  the 
concretions  consist  of  a  mixture  of  these  substances,  the  mag- 
nesium salt  being  the  most  abundant.  In  none  does  one  substance 
occur  in  a  pure  state.  Pigments  of  various  kinds,  and  more  or 
less  mucus  or  other  organic  constituents  of  the  framework  are 
also  present.  Phosphate  calculi  are  the  typical  "  secondary  " 
concretions,  and  they  are  formed  usually  in  the  bladder  as  a  con- 
sequence of  cystitis,  but  may  be  formed  in  the  renal  pelvis  or 
in  the  urethra.  In  some  cases  the  salts  are  precipitated  in  such 
large  quantities  that  they  form  great  masses  of  a  sediment  which 
does  not  aggregate  into  concretions.  Occasionally  stones  con- 
sisting principally  of  Ca3(PO4)2  or  CaHPO4  are  formed,  but 
these  are  rarities.  As  the  calcium  taken  in  the  food  is  chiefly 
eliminated  in  the  feces,  the  amount  in  the  urine  does  not  vary 
directly  with  the  amount  in  the  food,  and  the  formation  of 
phosphatic  concretions  is  always  a  matter  of  urinary  reaction 
and  not  of  diet.3  As  these  stones  fuse  to  a  black,  enamel- 
like  mass  under  the  blow-pipe,  they  have  been  called  "  fusible 
calculi." 

Calcium  carbonate  calculi  are  formed  frequently  in 
herbivora,  but  they  are  very  rare  in  the  urinary  passages  of 
man,  although  occurring  elsewhere  in  the  body  not  infrequently. 
Occasionally  these  are  soft  and  chalky,  but  if  well  crystallized, 
they  are  the  hardest  of  concretions. 

1  Baldwin,  Jour.  Exp.  Med.,  1900  (5),  27. 

2  See  Austin,  Boston  Med.  and  Surg.  Journal,  1901  (145),  181. 

3  Under  the  name   "  struyit  stone,"  Pommer   (Verb.  deut.  Path.  Gesell., 
1905  (9),  28)  describes  a  urinary  calculus  composed  of  very  pure  ammonio- 
magnesium  phosphate,  forming  the  hard,  rhombic  crystals  known  to  mineralo- 
gists as  "  struvit."      This  is  an  example  of  a  phosphate  stone  formed  inde- 
pendent of  ammoniacal  decomposition,  a  rare  occurrence. 


384   CALCIFICATION,    CONCRETIONS,  AND  INCRUSTATIONS 

Cystin  calculi  are   rare    but  very  interesting  formations. 
^      .      S-CH(NH2)-COOH  . 
Cystm   |  is  important  as  the  sulphur-containing 

S-CH(NH2)-COOH 

portion  of  the  proteid  molecule.  Under  normal  conditions  all 
the  cystin  taken  in  food  is  completely  oxidized  and  none  (or 
uncertain  traces)  appears  in  the  urine.  In  certain  individuals 
the  urine  contains  considerable  quantities  of  cystin  constantly 
(cystinuria,  see  Chap,  xix),  and  occasionally  in  these  cases  soft 
concretions  of  nearly  pure  cystin  are  formed  in  the  urinary 
passages.  Cystiu  calculi  may  reach  the  size  of  a  hen's  egg,  are 
crystalline  in  structure,  and  in  the  urine  of  such  patients  the 
characteristic  hexagonal  crystals  may  usually  be  found.  Loewy 
and  Neuberg  1  have  contended  that  the  cystin  found  in  urinary 
calculi  is  an  isomer  of  the  cystin  found  in  the  proteid  molecule, 
and  that  cystinuric  patients  can  completely  oxidize  proteid 
cystin,  but  not  the  stone  cystin.  This  claim  has  not  been  sub- 
stantiated, however.2 

Xanthin  Calculi. — Xanthin  is  the  most  abundant  of  the 
purin' bases  normally  present  in  urine,  but  the  total  amount  is 
extremely  small.  Like  uric  acid,  it  fluctuates  in  amount 
according  to  the  amount  of  destruction  of  nucleoproteids,  either 
of  the  food  or  of  the  tissues.  Concretions  consisting  chiefly 
of  xanthin,  which  is  often  mixed  with  uric  acid,  are  extremely 
rare,  but  a  few  isolated  specimens  having  been  described. 

Indigo  calculi,  derived  from  the  indican  of  the  urine 
through  oxidation,  have  also  been  described  a  few  times. 

Urostealith  calculi,  composed  of  fatty  matter,  have  been 
occasionally  observed.  Although  some  of  the  concretions  des- 
cribed under  this  head  have  really  represented  foreign  bodies 
introduced  through  the  urethra  (e.  g.,  Kruckenberg's  concretion 
of  paraffin  from  a  bougie),  yet  true  fat  concretions  do  occur. 
The  origin  of  the  fat  in  these  stealiths  is  unknown,  possibly 
it  comes  from  degenerated  epithelium.  Horbaczewski 3  analyzed 
such  a  specimen  which  had  the  following  percentage  composition  : 

Water      2.5 

Inorganic  matter       0.8 

Organic  matter  (chiefly  proteid)     .    . 11.7 

Fatty  acids 5.1.5 

Neutral  fat 33.5 

Cholesterin traces 

1  Zeit.  physiol.  Chem.,  1904  (43),  338. 

2  Rothera,  Jour,  of  Physiol.,  1905  (32),  175.     Literature  concerning  cystin, 
see  Friedmann.  Ergeb.  der  Physiol.,  1902  (i),  15;  Marriott  and  Wolf,  Am. 
Jour.  Med.  Sci.',  1906  (131),  197. 

3  Zeit.  physiol.  Chem.,  1894  (18),  335. 


URINARY  CALCULI  385 

The  fatty  acids  consisted  of  stearic,  palmitic,  and  probably 
myristic  acid. 

Cholesterin  calculi  have  been  found  in  the  urinary 
bladder  in  a  few  instances,  the  cause  being  unknown.  Horbac- 
zewski l  describes  one  weighing  25.4  grams,  found  in  a  patient 
who  had  previously  had  cystin  calculi ;  it  contained  95.87  per 
cent,  of  cholesterin  and  but  0.55  per  cent,  of  inorganic  material. 
Gall  stones  have  been  known  to  enter  the  urinary  bladder 
through  a  fistula  between  the  gall-bladder  and  urinary  bladder.2 

Fibrin  "  calculi,"  formed  from  blood-clots,  often  more  or 
less  impregnated,  with  urinary  salts,  have  occasionally  been 
observed.3 

General  Properties  of  Urinary  Concretions. — The 
hardness  depends  upon  the  chemical  composition  of  the 
calculus.  Those  composed  of  amorphous  phosphates  are  the 
softest ;  next  come  those  with  some  admixture  of  crystalline 
phosphates.  Urate  concretions  are  harder  than  these,  but  are 
still  softer  than  the  uric  acid  and  crystalline  phosphate  calculi. 
Oxalates  are  the  hardest,  except  for  the  rare  crystallized  calcium 
carbonate  stones.  Cystin  and  amorphous  concretions  can  be 
scratched  with  the  finger-nail,  while  even  the  hardest  varieties 
of  calculi  can  be  scratched  with  a  wire  nail.  Genersich4  gives 
the  following  degrees  of  hardness  for  different  calculi :  Choles- 
terin, 1.5-1.6;  ammonium  urate,  2.5  ;  soft  phosphate  (Mg), 
2.6  ;  hard  phosphate  (Ca),  2.75  ;  uric-acid  stones  (also  salivary 
and  prostatic  calculi,  atheromatous  patches,  and  phleboliths, 
2.9  ;  calcium  oxalate  (also  rhinoliths  and  lung  stones),  3.3—3.5  ; 
calcium  carbonate  stones  of  herbivora,  4.5. 

The  rate  of  growth  also  varies  according  to  composition, 
but  is,  of  course,  much  modified  by  other  factors.  Oxalate  and 
urate  stones  grow  most  slowly,  phosphate  stones  most  rapidly. 
A  urate  stone  has  been  known  to  increase  by  about  two  ounces 
during  seven  and  one  half  years,  while  a  catheter  fragment  or 
other  foreign  body  may  become  covered  with  a  crust  several 
millimeters  thick  in  a  few  weeks.5 

Spontaneous  disintegration  of  urinary  concretions  is  limited 
almost  solely  to  calculi  composed  entirely  or  largely  of  uric 

1  Loc.  cit. 

2  See  Finsterer,  Deut.  Zeit.  klin.  Chir.,  1906  (80),  426. 

3  Systems  for  procedure  in  determining  the  nature  of  urinary  calculi  are 
given  by  Hammarsten  (Text-book  of  Physiol.  Chern.)  and  by  Smith  (Kefer- 
ence  Handbook  of  Med.  Sci.,  1901  (3),  236). 

4  Virchow's  Arch.,  1893  (131),  185. 

5  Zuckerkandl,  Nothnagel's  System,  vol.  19,  pt.  2,  p.  229. 

25 


386   CALCIFICATION,   CONCRETIONS,  AND  INCRUSTATIONS 

acid.  Out  of  121  cases  collected  by  Englisch,1  in  all  but  7 
this  was  the  case,  these  being  composed  of  calcium  and  mag- 
nesium phosphate  (5),  or  calcium  phosphate  or  carbonate  (1 
each).  The  disintegration  is  brought  about  through  solution  of 
the  binding  substance  and  mechanical  shattering  of  the  stone 
into  fragments. 

CORPORA  AMYLACEA  2 

In  the  case  of  these  widely-spread  concentric  bodies  we  find 
the  name  misleading,  for  the  bodies  are  not  a  form  of  animal 
starch,  as  was  suggested  by  their  laminated  structure  and  iodin 
reaction,  nor  are  they  so  closely  related  to  amyloid  material  as 
the  name  implies.  Different  authors  disagree  decidedly  con- 
cerning the  staining  reactions  of  these  bodies,  but  it  may  be  said 
that  the  reactions  are  extremely  inconstant.  Sometimes  the 
corpora  are  stained  bluish  or  green  with  iodin,  sometimes  brown, 
often  little  at  all ;  occasionally  they  react  partly  with  methyl- 
violet,  but  more  often  they  do  not ;  sometimes  portions  of  one 
body  react  one  way,  while  the  remainder  behaves  differently. 
Seldom  if  ever  do  the  ordinary  concretions  of  the  prostate  give 
all  the  amyloid  reactions  characteristically,  and  the  same  applies 
to  the  corpora  amylacea  of  the  lungs.  It  seems  improbable 
that  these  bodies,  which  occur  in  the  prostate  of  every  adult 
(Posner),  can  be  the  same  as  the  amyloid,  which  is  seldom 
observed  except  as  the  result  of  serious  processes  of  tissue 
destruction.  According  to  their  structure  they  obey  the  usual 
laws  of  the  formation  of  concretions,  having  a  central  nucleus 
and  a  structural  framework  of  different  composition  from  the 
chief  substance.  It  seems  most  probable  that  they  should  be 
interpreted  as  simple  concretions  of  proteid  nature,  which  form 
under  certain  conditions  when  a  nucleus  of  some  sort  (usually 
pigment,  degenerated  cells,  or  inorganic  crystals)  exists  in  a 
stagnating,  proteid-rich  fluid.  At  times  the  resulting  concretion 
may  be  of  such  a  physical  nature  that  it  absorbs  iodin  readily 
(just  as  they  often  show  a  marked  absorption-affinity  for  pig- 
ments), and  occasionally  it  may  react  metachromatically  with 
methyl-violet,  possibly  because  of  the  presence  of  chondroitin- 
sulphuric  acid  derived  from  the  mucin  of  the  cavities  where 
the  concretions  form,  but  perhaps  for  some  other  unknown  rea- 
sons. Occasionally  pure  amyloid  may  form  in  the  tissues  typic- 
ally concentric  (or  even  crystalline)  bodies,  as  in  OphiiPs  case, 

1  Arch.  klin.  Chir.,  1905  (76),  961  (elaborate  review). 

2  General  literature,  Posner,  Zeit.  klin.  Med.,  1889  (16),  144;  Lubarsch, 
Ergeb.  allg.  Pathol.,  1894  (I2),  180;  Ophiils,  Jour.  Exp.  Med.,  1900  (5),  111. 


PANCREATIC  CALCULI  387 

but  this  is  the  exception.  It  seems  probable  that  corpora  amy- 
lacea  are  usually  proteid  concretions/  and  neither  amyloid  nor 
animal  starch. 

The  small  amount  of  material  available  prevents  an  accurate 
analysis  of  the  corpora  amylacea ;  it  is  known  that  they  are 
very  insoluble  in  water,  acids,  alkalies,  etc.,  behaving  like  coag- 
ulated proteid  in  this  respect.  Even  hot  concentrated  nitric 
acid  will  not  dissolve  them,  according  to  Posner.  This  author 
considers  lecithin  and  cholesterin  to  be  important  constituents, 
which  view  does  not  seem  to  have  been  confirmed.  The  cor- 
pora amylacea  of  the  lateral  ventricles  seem  to  consist  chiefly 
of  calcium  salts  deposited  in  a  concentric  arrangement  through 
the  medium  of  an  organic  basis.  Posner  considers  that  the 
presence  of  lecithin  in  prostatic  corpora  prevents  their  calcifica- 
tion, although  this  change  occasionally  does  occur. 

OTHER,  LESS  COMMON  CONCRETIONS 

Pancreatic  Calculi. — The  cause  of  the  formation  of  stones 
in  the  pancreatic  duct  is  not  definitely  known,  but  apparently 
infection  is  the  most  important  factor,  since  simple  experimental 
stasis  will  not  cause  their  formation.2  The  calculi  consist  usually 
of  a  mixture  of  calcium  phosphate  and  carbonate,  associated 
with  more  or  less  organic  matter,  including  frequently  choles- 
terin, but  all  the  usual  products  of  proteolysis  may  be  present 
because  of  the  presence  of  trypsin.  Occasionally  the  calculi 
consist  chiefly  of  calcium  carbonate,  which  may  be  almost  pure. 
Shattock3  has  observed  a  pancreatic  concretion  composed  of 
calcium  oxalate.  Sodium  phosphate  and  chloride,  magnesium 
phosphate,  and  proteids  have  also  been  found  in  these  concre- 
tions. 

Baldoni4  found,  on  analysis  of  a  stone  weighing  3.1  grams, 
the  following  percentage  composition  : 

Water .  3.44 

Ash 12.67 

Proteids 3.49 

Free  fatty  acids 13.39 

Neutral  fatty  acids 12.40 

Cholesterin 7.69 

Pigments  and  soap 40.91 

Undetermined 6.01 

1  Eamsden's  observations  (Proc.  Koyal  Soc.,  1903  (72),  156)  on  the  precipi- 
tation of  proteids  by  the  action  of  surface  contact  may  have  some  bearing  on 
the  formation  of  such  proteid  concretions. 

2  See  Lazarus,  Zeit.  klin.  Med.,  1904  (51),  530.     Literature. 

3  Brit.  Med.  Jour.,  1896  (i),  1034. 

4 Schmidt's  Jahrb.,  1900  (268),  210. 


388   CALCIFICATION,   CONCRETIONS,   AND  INCRUSTATIONS 

Usually,  however,  pancreas  stones  consist  chiefly  of  inorganic 
substances.  Johnson  and  Wollaston  report  analyses  of  two 
stones,  one  containing  72.30  per  cent,  calcium  phosphate  and 
but  8.80  per  cent,  organic  matter;  the  other  91.65  per  cent, 
calcium  carbonate,  4.15  per  cent,  magnesium  carbonate,  and 
but  3  per  cent,  organic  matter.  Legrand  1  found  only  0.7  per 
cent,  organic  matter  in  another  concretion  which  contained  93.1 
per  cent,  calcium  carbonate.  Pancreatic  juice,  being  strongly 
alkaline,  can  hold  but  a  small  quantity  of  calcium  salts  in  solu- 
tion (normally  but  0.22  part  per  thousand — C.  Schmidt);  pre- 
sumably the  little  normally  present  is  held  in  the  form  of  a 
colloidal  suspension  by  the  proteids.  Possibly  when  stasis 
occurs,  digestion  of  the  proteids  leads  to  the  precipitation  of 
the  calcium  salts,  or,  more  probably,  the  excessive  calcium  is 
largely  derived  from  the  exudate  from  the  inflamed  ducts,  as 
seems  to  be  the  case  with  the  calcium  of  biliary  calculi. 

Salivary  Calculi.2 — These  have  a  similar  composition,  in 
the  main,  to  the  concretions  of  the  pancreatic  duct,  except  that 
they  generally  contain  more  organic  matter,  resembling  in  this 
respect  the  "  tartar"  of  the  teeth.  Bessanez  found  in  one  81.3 
per  cent,  of  calcium  carbonate  and  4.1  per  cent,  of  calcium  phos- 
phate, whereas  in  another  the  carbonate  was  but  2  per  cent,  and 
the  phosphate  75  per  cent.  Potties  has  described  a  calculus 
with  a  central  portion  composed  chiefly  of  uric  acid  and  a  periph- 
eral portion  containing  69  per  cent,  of  calcium  phosphate  and 
20.1  per  cent,  of  calcium  carbonate.  Harlay3  found  in  one 
specimen  15.9  per  cent,  organic  matter,  75.3  per  cent,  calcium 
phosphate,  6.1  per  cent,  calcium  carbonate.  Eoberg  believes 
that  bacteria  alone  do  not  usually  cause  salivary  calculi  to 
form,  but  that  a  foreign  body  entering  the  duct  is  the  chief 
factor.  Increased  alkalinity  may  also  favor  precipitation  of 
calcium  from  the  saliva.  In  Koberg's  case  of  sialolithiasis  the 
saliva  was  of  normal  composition. 

Intestinal  Concretions. — These  always  have  a  nucleus 
of  some  indigestible  foreign  substance,  most  often  hair,  but 
sometimes  cellulose  structures  or  solid  indigestible  particles, 
including  gall-stones,  fruit-stones,  bone,  etc.  The  bulk  of  the 
concretions  is  usually  made  up  chiefly  of  ammonio-magnesium 
phosphate,  with  some  calcium  phosphate,  carbonate,  and  sul- 
phate, proteid  matter,  and  occasionally  calcium  and  magnesium 

1  Jour.  Pharm.  et  Chim.,  1901  (14),  21. 

2  Literature,  see  Roberg,  Annals  of  Surgery,  1904  (39),  669. 

3  Jour.  Pharm.  et  Chim.,  1903  (18),  11. 


INTESTINAL  CONCRETIONS  389 

soaps.  Two  intestinal  concretions  analyzed  by  Schuberg  1  had 
the  following  percentage  composition  when  dried  : 

Ammonio-magnesium  phosphate 57.1  63.9 

Calcium  phosphate 15.7  23.8 

Calcium  carbonate   .    .        ...  4.6 

Calcium  sulphate 3.0  0.7 

Alcohol-ether  extract 1.9  0.8 

Other  organic  substances 21.5  6.0 

In  countries  where  oatmeal  is  largely  eaten,  intestinal  concre- 
tions are  not  infrequent ;  they  contain  calcium  and  magnesium 
phosphate,  about  70  per  cent. ;  oatmeal  bran,  15-18  per  cent. ; 
soaps  and  fats,  about  10  per  cent.  (Hammarsten).  Occasion- 
ally concretions  consisting  largely  of  fat  and  soaps  are  found, 
and  after  taking  large  doses  of  olive  oil  masses  of  solidified  oil 
may  be  passed  that  are  readily  mistaken  for  softened  gall-stones, 
for  the  removal  of  which  the  oil  is  usually  given. 

Bezoar  stones  are  intestinal  concretions  probably  coming 
from  Capra  cegagrus  and  Antelope  dorcas.  One  variety  consists 
chiefly  of  lithofellic  acid,  C20H36O4,  which  is  related  to  cholalic 
acid,  and  gives  an  aromatic  odor  when  heated.  The  other 
variety  ("  false  bezoars  ")  does  not  give  the  aromatic  odor,  and 
consists  chiefly  of  ellagic  acid,  C14H6O8,  a  derivative  of  gallic 
acid,  and,  therefore,  probably  derived  from  the  tannin  of  the 
food  of  the  antelopes. 

Intestinal  *«  sand  "  occurs  as  (1)  "false  sand/7  consisting  of 
particles  of  indigestible  food,  such  as  the  sclerenchymatous 
particles  in  the  flesh  of  pears ;  and  (2)  true  sand,  consisting 
largely  of  inorganic  material,  and  formed,  according  to  Duck- 
worth and  Garrod,2  in  the  upper  part  of  the  large  intestine. 
Analyses  of  specimens  by  Garrod  showed  the  following  com- 
position : 

. .  if—  .f 

[  traces  of  Mg,  Fe,  etc.    .    .    .     0.47 

Analyses  by  other  observers  have  given  similar  results,  the 
absence  of  the  large  proportion  of  magnesium  found  in  larger 
concretions  being  striking. 

The  color  is  usually  brown,  due  chiefly  to  urobilin,  unaltered 
bile-pigments  being  scanty. 

Preputial  concretions  sometimes  form  beneath  a  prepuce 
that  cannot  be  retracted,  through  deposition  of  urinary  salts  on 

1  Virchow's  Arch.,  1882  (90),  73. 

2  Lancet,  1902  (i),  653.     Full  resume  and  literature. 


390   CALCIFICATION,    CONCRETIONS,   AND  INCRUSTATIONS 

and  in  the  accumulated  smegma.1  The  composition  is,  there- 
fore, very  mixed,  and  consists  of  an  organic  base  containing 
much  cholesterin,  fats,  and  soaps,  incrusted  with  inorganic  sub- 
stances, of  which  ammonio-magnesium  phosphate  and  calcium 
phosphate  are  usually  the  most  abundant. 

Prostatic  concretions  originate  in  the  corpora  amylacea 
(which  have  been  discussed  on  page  386)  through  growth  by 
accretion  of  inorganic  salts,  until  they  may  reach  considerable 
size.  Stern  2  gives  the  following  results  of  analysis  of  such  a 
prostatic  stone  : 

Water   ........    ...»    ...........    8.0 

Organic  matter    ...................  15.8 

Lime     .......................  37.64 

Magnesia  ......................    2.38 

Soda  ......................        1.76 

Potash  .......................    0.5 

Phosphoric  acid  ...............    ....  33.77 

Iron  ......................          trace 


Stones.3  —  These  may  be  formed  in  the  bronchi, 
through  accretion  about  an  inorganic  nucleus,  similar  to  the 
formation  of  calculi  in  other  epithelial-lined  passages  ;  or  they 
may  consist  of  calcined  areas  of  lung  tissue  or  peribronchial 
glands,  which  have  been  sequestrated  through  suppuration  and 
have  entered  the  bronchi.  In  the  latter  case,  the  calculi 
present  the  usual  composition  of  pathological  calcified  areas. 
That  the  expectorated  stones  frequently  represent  calcified 
tubercles  is  shown  by  Stern  3  and  by  Biirgi,3  who  demonstrated 
tubercle  bacilli  in  decalcified  lung  stones.  The  following  per- 
centage figures  are  taken  from  Ott  4  : 

Specimen  I.          Specimen  II. 

Calcium  phosphate  ...........  52.0  72.8 

Magnesium  phosphate     ...........  1.0 

Magnesium  carbonate      .........    2.0 

Calcium  carbonate    ...........  13.0  6.0 

Fat  and  cholesterin  ...........  24.0  7.0 

Other  organic  substances    .    .......    4.0  10.0 

Rhinoliths5  are  formed  about  nasal  secretions,  blood-clots, 
and  most  frequently  about  foreign  bodies.  They  therefore 
contain  much  organic  substance  in  addition  to  the  inorganic 

1  See  Zeller,  Arch.  klin.  Chir.,  1890  (41),  240. 

2  Amer.  Jour.  Med.  Sci.,  1903  (126),  281. 

3  Literature,  Poulalion,  Thesis,  Paris,  1891  ;  Stern,  Deut.  med.  Woch.,  1904 
(30),  1414.     Biirgi  (Deut.  med.  Woch.,  1906  (32),  798)  has  recently  described 
two  cases  in  which  the  concretions  consisted  chiefly  of  calcium  phosphates. 

4  "  Chem.  Path,  der  Tuberc.,"  1903,  p.  92. 

5  Literature,  Scheppegrell,  Jour.  Amer.  Med.  Assoc.,  1896  (26),  874  ;  Gerber, 
Deut.  med.  Woch.,  1892  (18),  1165. 


CUTANEOUS    CONCRETIONS 


391 


salts  deposited  upon  them.     Berlioz l  gives  the  following  table 
from  the  analysis  of  four  specimens  : 


Weight  of  specimens,  grams    

1 
3.75 

2 
1.34 

3 

0.63 

4 

0.95 

Water           

5.80 

5.10 

4.00 

6.90 

16.60 

18.20 

16.00 

18.10 

Calcium  phosphate      

62.02 

508 

60.61 

6.28 

61.40 
3.93 

47.63 
6.68 

10.50 

9.81 

14.67 

20.69 

Traces  of  iron          •    

Doubtful. 

Distinct. 

Doubtful. 

Distinct. 

Tonsillar  concretions  consist  chiefly  of  carbonate  and 
phosphate  of  calcium  deposited  upon  the  inspissated  secretions 
and  desquamated  cells  of  the  tonsillar  crypts.  According  to 
some  authors,  leptothrix  threads  frequently  form  the  nucleus  of 
the  concretions. 

Cutaneous  concretions  are  occasionally  observed,  located 
chiefly  in  the  subcutaneous  tissue,  often  occurring  multiple. 
The  origin  is  possibly  in  dilated  sebaceous  glands  with  retained 
secretions.  Unna  considers  that  calcium  soaps  are  formed  as  a 
first  step,  but  an  analysis  of  such  material  by  Harlay 2  showed 
87.2  per  cent,  of  ash,  12.8  per  cent,  organic  matter,  0.9  per 
cent,  of  fat ;  calcium  phosphate  constituted  65.2  per  cent.,  and 
calcium  carbonate  16.4  per  cent.  Gascard3  found  in  similar 
material  23.4  per  cent,  organic  matter,  and  of  the  inorganic 
matter,  91.1  per  cent,  was  calcium  phosphate,  and  8.9  per  cent, 
calcium  carbonate. 

Gouty  deposits  observed  in  the  subcutaneous  tissues,  as  well 
as  along  the  tendons,  articular  cartilages,  etc.,  consist  usually  of 
nearly  pure  biurate  of  sodium  and  potassium.  Ebstein  and 
Sprague 4  found  the  composition  of  such  material  to  be  as  follows  : 

Uric  acid      59.70 

Tissue  organic  matter 27.88 

Sodium  oxide 9.30 

Potassium  oxide 2.95 

Calcium  oxide 0.17 

MgO,  Fe,  PA,  S .  traces 

After  a  time,  however,  calcium  salts  may  be  deposited,  and 
Dunin 5  has  observed  deposits  resembling  gouty  tophi  that  were 
merely  calcium  salts. 

1  Jour.  Pharm.  et  Chim.,  1891  (23),  447. 

2  Jour.  Pharm.  et  Chim.,  1903  (18),  9. 
3/6id,  1900  (12),  262. 

4  Virchow's  Arch.,  1891  (125),  207. 

5  Mitt.  Grenzgeb.  Med.  u.  Chir.,  1905  (14),  451. 


392   CALCIFICATION,    CONCRETIONS,   AND  INCRUSTATIONS 
PNEUMONOKONIOSIS 

In  a  number  of  cases  of  the  different  forms  of  this  condition 
quantitative  analyses  have  been  made,  which  may  be  briefly 
discussed  as  follows  :  Not  only  does  tl^e  lung  of  every  adult 
contain  considerable  amounts  of  coal-pigment  stored  up  in  the 
connective  tissues  (and  also  in  the  peribronchial  glands),  but 
also,  which  is  perhaps  less  generally  appreciated,  considerable 
quantities  of  silicates  are  also  present  (chalicosis)  from  inhaled 
dust.  Woskressensky l  found  silicates  in  all  of  54  lungs 
examined,  except  two  from  infants.  The  lungs  of  individuals 
whose  occupations  do  not  expose  them  especially  to  dust  inhala- 
tion contain  increasing  amounts  of  silicates  in  direct  proportion 
to  age ;  the  silicates  constitute  then  from  3.5  to  10  per  cent,  of 
the  total  ash  of  the  lungs.  There  is  always  a  larger  proportion 
of  silicates  in  the  peribronchial  glands  than  in  the  lungs,  con- 
stituting from  6  to  36  per  cent,  of  the  ash,  corresponding  with 
Arnold's  observation  that  in  gold-beaters  the  glands  contain 
more  metal  than  the  lungs.  In  stone-workers  Schmidt  found  a 
higher  proportion  of  SiO2  in  the  lungs  than  in  the  glands.  In 
normal  adults  the  amount  of  coal-pigment  is  greater  than  the 
amount  of  silicates ;  in  children  the  reverse  is  the  case. 

Thorel 2  reports  that  the  lungs  of  a  worker  in  soapstone  con- 
tained 3.25  per  cent,  of  ash,  including  2.43  per  cent,  of  soap-stone. 

In  siderosis  iron  has  been  found  in  the  lungs  in  proportions 
varying  from  0.5  per  cent,  to  7.9  per  cent,  of  the  dry  weight, 
the  last  amount  having  been  found  by  Langguth 3  in  the  lungs 
of  an  iron  miner,  which  contained  also  11.92  per  cent,  of  SiO2. 

An  analysis  of  a  lung  from  a  knife-grinder  is  reported  by 
Hodenpyl,4  which  gave  the  following  results  :  Total  weight  of 
dried  and  powdered  lung,  48.1009  grams  ;  total  solids,  44.7986  ; 
ether-soluble  substance,  14.6017.  Composition  of  the  ether- 
soluble  substance  :  free  fatty  acids,  7.498;  neutral  fats,  4.044  ; 
cholesterin,  3.037.  Proteids,  15.4759  ;  charcoal  (total  carbon 
less  proteid  carbon),  7.198  ;  ash,  4.2903.  The  composition  of 
the  ash  (in  grams)  was  as  follows  :  K2O,  0.2167  ;  Na2O, 
0.3523;  CaO,  0.0965;  Fe9O3,  0.0879;  A12O3,  1.4628;  SO3, 
0.0704 ;  P2O5,  0.9565  ;  SiO2,  1.2043.  The  amount  of  emery, 
represented  by  the  oxides  of  aluminum  and  silicon  made  up 
more  than  one-half  of  the  ash,  and  the  iron  constituted  about 
one-fourth.  The  man  had  worked  at  the  trade  of  knife-grinder 
for  about  fifteen  years. 

•  1  Cent.  f.  Path.,  1898  (9),  296.  2  Ziegler's  Beitr.,  1896  (20),  85. 

3  Deut.  Arch.  klin.  Med.,  1895  (55),  255.    4  Medical  Record,  1899  (56),  942. 


CHAPTER   XVI 
PATHOLOGICAL  PIGMENTATION 

MELANIN1 

Melanin  occurs  normally  as  the  coloring-matter  of  hair,  of 
the  choroid  of  the  eye,  of  the  skin,  in  the  pigment  matter  of 
many  lower  animals,  and  most  strikingly  as  a  defensive  sub- 
stance in  the  "  ink  "  ejected  by  squids  to  render  themselves 
invisible  in  the  water.  Pathologically  melanin  occurs  chiefly 
as  the  result  of  an  excessive  production  of  this  pigment  by  cells 
normally  forming  it,  as  in  freckles,  melanotic  tumors,  and 
Addison's  disease  (probably).  Cells  that  do  not  normally  form 
melanin  probably  do  not  acquire  this  power  in  pathological 
conditions.  Pathological  failure  to  form  melanin  is  also 
observed,  as  in  skin  formed  in  the  healing  of  wounds  and  after 
syphilitic  lesions ;  or  in  albinism,  in  which  the  failure  to  form 
melanin  may  often  be  attributed  to  hereditary  influences. 

Melanin  seems  always  to  be  produced  through  metabolic 
activity  of  specialized  cells.  The  idea,  which  was  formerly 
advanced,  that  it  is  derived  from  hemoglobin  as  a  product  of 
disintegration,  seems  to  have  failed  entirely  of  substantiation. 
In  malaria  we  frequently  find  a  diffuse  pigmentation  of  the  skin 
of  such  a  nature  as  to  suggest  strongly  a  melanin  formation,  and 
this  has  been  cited  as  an  example  of  the  production  of  melanin 
from  hemoglobin.  Carbone  has  proved,  however,  that  this 
malarial  pigment  is  derived  from  hematin.  The  amount  of 
iron  contained  in  melanin  has  been  much  investigated, 
as  bearing  upon  the  question  as  to  whether  the  melanin  is 
derived  from  hemoglobin  or  not,  and  the  results  obtained  by 
the  best  methods  indicate  that  the  amount  of  iron  present  is 
usually  extremely  small,  and  often  it  is  entirely  absent ;  further- 
more, the  presence  of  iron  is  no  proof  that  the  pigment  is 
derived  from  hemoglobin,  since  many  other  proteids  contain  iron. 

Composition  of  Melanin. — The  elementary  composition 
of  different  specimens  of  melanin  examined  by  various  observers 
has  been  found  to  vary  greatly.  This  probably  depends  on 

1  Literature  and  re'sume'  given  by  v.  Fiirth,  Cent.  f.  Pathol.,  1904  (15),  617, 
hence  only  special  references  will  be  cited  in  the  following  discussion. 

393 


394  PATHOLOGICAL  PIGMENTATION 

three  factors  :  First,  it  is  extremely  difficult  to  obtain  melanin 
in  a  pure  condition ;  second,  the  process  of  purification  requires 
the  action  of  strong  acids  and  alkalies,  which  undoubtedly 
modify  the  composition  of  the  melanin  ;  thirdly,  melanin  is 
probably  not  a  single  substance  of  definite  composition,  but 
includes  several  related  but  different  bodies.  The  values  found 
vary  for  carbon  from  48.95  to  60.02  per  cent.;  for  hydrogen 
from  3.05  to  7.57  per  cent.;  for  nitrogen,  8.1  to  13.77  per  cent. 
Hofmeister  gives,  as  a  characteristic  of  melanins,  that  their 
elementary  molecular  composition  is  always  nearly  in  the  pro- 
portions N:H:C=1:5:5. 

A  particularly  prominent  constituent  of  melanin  is  sulphur, 
which  has  been  found  in  as  high  proportions  as  10  per  cent,  in 
melanin  from  sarcomas,  and  even  12  per  cent,  in  sepia  from  the 
squid ;  in  melanin  from  hair  the  sulphur  is  usually  about  2-4 
per  cent.;  but  in  choroid  melanin,  and  in  some  other  forms,  sul- 
phur seems  to  be  absent.  The  proportions  of  sulphur  obtained 
from  the  same  specimen  purified  by  different  methods  show 
wide  variations,  and  hence  v.  Fiirth  considers  that  neither  the 
sulphur  nor  the  iron  are  indispensable  constituents  of  the  mel- 
anin. Probably  the  melanin  molecule  contains  atom-complexes 
that  have  a  tendency  to  bind  certain  sulphur  and  iron  com- 
pounds (e.  g.,  cystin  or  hematin  derivatives). 

There  is  much  reason  to  believe  that  the  melanin  is  derived 
from  certain  groups  of  the  proteid  molecule  that  seem  readily  to 
form  colored  compounds.  The  aromatic  compounds  of  the  pro- 
teid molecule,  such  as  tyrosin,  phenylalanin,  and  tryptophan, 
readily  condense  with  elimination  of  water  and  absorption  of 
oxygen,  to  produce  dark -colored  substances.  When  proteids  are 
heated  in  strong  hydrochloric  acid,  we  obtain  a  dark-brown 
material,  which  closely  resembles  the  melanins  both  in  element- 
ary composition  and  in  general  properties,  so  that  it  is  referred 
to  as  "  artificial  melanin  "  or  "  melanoid  substance."  These 
substances,  like  the  natural  melanins,  when  decomposed  by 
fusing  with  caustic  potash,  yield  skatol,  indol,  and  pyrrol  deriv- 
atives, which  are  undoubtedly  derived  from  the  tyrosin  and 
tryptophan  of  the  proteid  molecule.  Therefore,  it  seems  prob- 
able that  both  the  melanoid  substances  and  the  true  melanins 
are  formed  from  the  chromogen  groups  of  the  proteid  molecule 
through  processes  of  condensation,  elimination  of  water,  and 
the  taking  up  of  oxygen. 

Tyrosinase. — In  the  sepia  sacs  of  the  cuttle-fish,  in  meal- 
worms which  form  a  melanin-like  pigment,  and  in  plants  that 
produce  the  black  Japanese  lacquer,  have  been  found  oxidizing 


MELANIN  395 

enzymes  that  have  the  property  of  producing  black  pigment  by 
their  action  upon  tyrosin  and  other  aromatic  compounds.  These 
enzymes  may,  therefore,  possibly  be  responsible  for  the  produc- 
tion of  melanin  in  animal  tissues,  by  causing  oxidative  changes 
in  the  chromogen  groups  of  the  proteid  molecule  that  are 
liberated  by  autolysis  (see  "Tyrosinase  "  p.  79).  v.  Fiirth  urges 
strongly  the  view  that  both  normal  and  pathological  melanin 
formation  depends  upon  the  action  of  tyrosinase  or  allied  enzymes 
in  conjunction  with  autolytic  enzymes  ;  the  latter  split  free  the 
chromogen  groups  of  the  proteid  molecule,  which  are  then  oxi- 
dized by  the  tyrosinase,  undergo  condensation,  and  take  up  sul- 
phur- and  iron-holding  groups  and  also  other  organic  compounds, 
the  entire  complex  forming  the  melanin. 

Properties  of  Melanin. — When  isolated  in  a  pure  con- 
dition, melanin  is  a  dark-brown  substance  of  amorphous  struc- 
ture, no  matter  how  black  the  material  from  which  it  is  derived 
may  be.1  It  is  quite  insoluble  in  all  ordinary  reagents  except 
alkalies,  in  which  some  melanins  dissolve  easily,  and  some  with 
difficulty.  Strong  boiling  hydrochloric  acid  scarcely  affects 
melanin.  By  the  action  of  sunlight  or  oxidizing  agents  on 
melanin-containing  sections  the  pigment  can  be  bleached  out. 
The  chief  decomposition-products  formed  on  fusing  with  alka- 
lies are  indol,  skatol,  and  "  melanic  acid  "  ;  no  cystin,  leucin, 
tyrosin,  or  other  amino-acids  can  be  isolated.  Most  authors, 
therefore,  consider  the  melanins  as  heterocyclic  compounds 
standing  in  some  relation  to  the  indol  nucleus. 

If  melanin  is  injected  subcutaneously  into  animals  (rabbits  and 
guinea-pigs),  there  appears  in  the  urine  a  substance  which  turns 
dark  brown  after  the  urine  has  stood  for  some  time  (Robert, 
Helman).  The  pigment  is  apparently  reduced,  particularly  by 
the  liver,  to  a  colorless  melanogen,  which  is  eliminated  in  the 
urine.  The  same  process  occurs  when  melanin  is  produced  in 
excess  and  enters  the  blood,  as  in  the  case  of  melanosarcoma,  a 
colorless  melanogen  being  formed  which  is  excreted  in  the 
urine,  constituting  "  melanuria."  Occasionally  the  urine  is 
dark  when  first  passed,  because  of  the  presence  of  melanin,  but 
usually  it  must  be  subjected  to  oxidizing  agencies  (bromine 
water,  nitric  acid,  hypochlorites,  etc.),  or  exposed  to  air  to 
bring  out  the  brown  color.  Helman 2  says  that  true  melanogen 
may  be  considered  to  be  present  in  urine:  (1)  If  the  careful 

*Spiegler  (Hofmeister's  Beitr.,  1903  (4),  40)  claims  to  have  isolated  a 
white  chromogen,  closely  related  to  melanin  chemically,  which  causes  the 
white  color  of  wool  and  hair. 

2  Cent.  f.  inn.  Med.,  1902  (23),  1017;  Arch,  internat.  Pharmakodynam., 
1903  (12),  271. 


396  PATHOLOGICAL  PIGMENTATION 

addition  of  ferric  chloride  causes  the  development  of  a  black 
precipitate.  (2)  If  this  precipitate  dissolves  in  sodium  car- 
bonate, forming  a  black  solution.  (3)  If  from  this  solution  min- 
eral acids  precipitate  a  black  or  brownish-black  powder.  All 
three  reactions  must  be  obtained,  for  substances  other  than 
melanin  may  give  the  first  two. 

The  coloring  power  of  melanin  is  very  great,  for  urine  con- 
taining but  0.1  per  cent,  of  melanin  has  the  color  of  dark  beer 
(Hensen  and  Nolke),  and'  the  entire  skin  of  a  negro  contains 
only  about  1  gram  of  melanin  (Abel  and  Davis  *).  Excessive 
quantities  of  melanin  may  be  in  part  deposited  in  the  lymph- 
glands  and  skin,  causing  diffuse  pigmentation ;  it  may  also  be 
deposited  in  the  endothelium  lining  the  blood-vessels.  Kobert 
injected  melanin  into  albino  rabbits,  but  did  not  succeed  in  get- 
ting any  deposition  in  the  choroid  or  skin.  Helman  found 
some  evidence  of  toxicity  when  large  doses  of  melanin  dissolved 
in  sodium  carbonate  are  injected  into  animals,  but  this  is  pos- 
sibly due  to  the  alkali  rather  than  to  the  melanin. 

Melanotic  Tumors. — Tumor  melanin  does  not  differ  from 
melanin  produced  by  normal  cells  in  any  essential  respect. 
Usually  it  contains  much  sulphur,  even  as  much  as  10  per  cent., 
yet  Helman  in  eight  specimens  found  but  four  that  contained 
both  sulphur  and  iron,  in  three  only  sulphur,  in  one  only  iron 
and  no  sulphur;  therefore,  tumor  melanins  show  the  same 
variations  in  composition  as  do  normal  melanins.  Iron  is  fre- 
quently found  microscopically  in  the  pigment  in  melanosar- 
coma,  but  this  is  chiefly  due  to  admixture  of  blood-pigment 
coming  from  extravasations  of  blood.  The  peculiar  fact  that 
melanosarcoma  is  very  common  in  white  or  gray  horses,  but 
very  seldom  occurs  in  dark -coated  horses,  has  not  been  explained. 
The  frequent  occurrence  of  melanuria  and  melanemia  in  patients 
with  melanosarcoma  is  not  due  to  any  peculiar  property  of 
sarcoma  melanin,  but  to  the  enormous  quantity  of  melanin  that 
is  produced  by  the  tumor  and  set  free  in  the  degenerating  por- 
tions. Thus,  while  Abel  and  Davis1  estimate  that  there  is 
only  about  1  gram  of  melanin  in  the  entire  skin  of  a  negro, 
Nencki  and  Berdez  have  obtained  from  a  sarcomatous  liver  300 
grams  of  melanin,  and  estimate  that  the  entire  body  contained 
500  grams.  Helman 2  states  that  the  melanin  may  constitute 
7.3  per  cent,  by  weight  of  the  fresh  substance  of  some  melano- 
sarcomas.  According  to  Lubarsch  and  to  Helman,  melanotic 
tumors  rarely  contain  glycogen. 

1  Jour.  Exp.  Med.,  1896  (1),  361. 

2  Arch,  internal.  Pharmakodynam. ,  1903  (12), 271. 


MELANIN  397 

Addison's  disease  is  associated  with  the  deposition  of  a 
pigment  in  the  skin  that  is  generally  considered  to  be  a  melanin, 
differing  from  that  produced  normally  in  the  skin  only  in 
quantity  and  not  in  origin  or  composition.1  No  satisfactory 
explanation  of  the  relation  of  the  adrenal  to  this  pigmentation 
seems  yet  to  have  been  made,  although  it  is  natural  to  assume 
that  when  the  function  of  the  adrenal  is  destroyed,  substances 
accumulate  in  the  blood  that  have  a  stimulating  effect  on 
the  pigment-forming  cells.  Abnormal  proteid  katabolism,  with 
excessive  accumulation  of  the  chromogenic  constituents  of  the 
proteid  molecule,  has  been  suggested,  as  also  have  alterations 
in  the  influence  of  the  sympathetic  nervous  system  upon  the 
chromophore  cells,  for  nerve  lesions  (e.  g.y  neurofibroma)  are 
often  accompanied  by  pathological  pigmentation  of  the  skin.2 
As  exact  chemical  studies  of  the  pigment  in  Addison's  disease 
have  not  been  made,  however,  we  have  no  positive  proof  that 
it  is  a  melanin,  hence  any  speculation  as  to  the  cause  of  its 
formation  is  premature.  Carbone 3  claims  to  have  isolated  from 
the  urine  in  Addison's  disease  a  pigment  that  contains  much 
sulphur,  and  which  he  considers  similar  to  or  identical  with  the 
melanogen  of  melanuria.  v.  Kahlden,4  however,  has  observed 
crystals  resembling  hematoidin  in  the  pigmented  tissues. 

Ochronosis  is  a  condition  characterized  by  a  black  pigmen- 
tation of  the  cartilages,  first  described  by  Virchow  in  1866. 
In  1904  Osier5  reported  two  cases,  and  found  but  seven  others 
in  the  literature  to  that  time.  The  origin  and  nature  of  this 
pigment  remain  still  undecided.  Virchow  suspected  that  the 
condition  was  due  to  a  permeation  of  cartilage  by  hematin 
derivatives,  but  Hansemann,  finding  a  case  associated  with 
melanuria,  considered  that  the  pigment  is  probably  of  meta- 
bolic origin.  Hecker  and  Wolf  studied  the  urine  of  a  similar 
case,  and  concluded  that  the  pigment  must  be  melanin. 
Albrecht,6  however,  suggested  a  relation  of  ochronosis  to  alkap- 
tonuria, having  found  hemogentisic  acid  in  the  urine  of  a  case 
reported  by  him  (see  "  Alkaptonuria  ").  Osier's  two  patients 
were  brothers  with  alkaptonuria,  the  evidence  of  ochronosis  con- 
sisting of  discoloration  of  the  cartilages  of  the  ears.  Langstein7 

1  Concerning  histogenesis  of  the  pigment  see  Pforringer,  Cent.  f.  Path.. 
1900(11),!. 

2  See  resume*  by  Schmidt,  Ergeb.  der  Pathol.,  1896  (Bd.  3,  Abt.  1),  551. 

3  Giorao  R  Acad.  med.  di  Torino,  1896. 

4  Virchow's  Arch.,  1888  (114),  65. 

5  Lancet,  1904  (i),  10  (literature). 

6Zeit.  f.  Heilk.,  Path.  Abt.,  1902  (23),  366. 
7  Hofmeister's  Beitr.,  1903  (4),  145. 


398  PATHOLOGICAL  PIGMENTATION 

has  examined  a  specimen  of  urine  preserved  from  Hansemann's 
case,  and  found  no  evidence  of  alkaptonuria.1 

Pick 2  has  recently  added  another  case  to  the  literature,  and 
he  summarizes  the  results  of  his  study  of  this  case  and  of  the 
literature,  as  follows  :  Ochronosis  is  a  definite  form  of  mela- 
notic  pigmentation,  the  pigment  of  ochronosis  being  in  most  of 
the  cases  very  closely  related  to  melanin.  The  pigment,  or  its 
chromogen,  circulating  freely  in  the  blood,  is  imbibed  not  only 
by  cartilage,  but  also  by  loose  connective  tissue,  voluntary  and 
involuntary  muscle-cells,  and  epithelial  cells,  without  any  decrease 
in  vitality  of  these  cells  being  observable ;  however,  degenerated 
tissues  show  the  greatest  amount  of  pigmentation.  The  diffuse 
pigment  can  become  granular  after  a  time ;  it  is  iron-free,  but 
under  certain  circumstances  may  contain  fat.  This  melanin 
arises  from  the  aromatic  nucleus  of  the  proteid  molecule  (tyrosin, 
phenylalanin),  and  the  related  hydroxylized  products,  under  the 
influence  of  tyrosinase.  In  two  cases  the  constant  absorption 
of  minute  quantities  of  phenol  from  surgical  dressings  seems 
to  have  been  the  cause  of  the  condition.  Besides  this  formation 
of  pigment  from  such  "  exogenous  "  aromatic  substances,  how- 
ever, it  is  probable  that  in  alkaptonuria  the  "  endogenous " 
aromatic  substances  (alkaptonuric  acids)  present  may  be  con- 
verted into  pigment  by  the  tyrosinase.  In  many  of  the  cases 
of  ochronosis  the  pigment  or  a  precursor  may  be  excreted  in  the 
urine,  which  then  undergoes  spontaneous  darkening  when  exposed 
to  the  air.  The  kidneys  may  also  become  pigmented,  and  gran- 
ular masses  of  pigment  may  be  present  in  the  renal  tubules. 

Malarial  pigmentation  has  been  studied,  particularly  by 
Ewing,3  who  states  that  in  malarial  fever  one  may  meet  with 
granular,  sometimes  crystalline,  pigment  particles,  free  in  the 
vessels  or  englobed  in  various  cells,  not  giving  the  Prussian- 
blue  reaction,  nor  dissolving  in  chloroform,  ether,  or  carbon 
bisulphide,  but  dissolving  in  ammonium  sulphide.  This  pig- 
ment may  have  any  one  of  the  following  origins  : 

(1)  Pigment  elaborated  by  the  intracellular  parasite.  (2) 
Hematoidin  derived  from  the  remnants  of  infected  red  cells. 
(3)  Hematoidin  or  altered  hemoglobin  deposited  in  granular  or 
crystalline  form  from  red  cells  dissolved  in  the  plasma.  (4) 
Bilirubin  or  urobilin  granules  or  crystals. 

Of  these,  the  pigment  formed  by  the  parasites  has  been  con- 
sidered by  many  as  a  true  melanin,  but  this  cannot  be  considered 

1  Also  see  Langstein,  Berl.  klin.  Woch.,  1906  (43),  597. 
2Berl.  klin.  Wochenschr. ,  1906  (43),  478. 
3  Jour.  Exp.  Med.,  1902  (6),  119. 


LIPOCHROME  399 

as  established,  especially  as  Ewing  finds  it  to  have  the  same 
relation  to  solvents  as  do  the  blood-pigments. 

LIPOCHROME 

Iii  normal  plant  and  animal  tissues  occur  pigments  that  are 
either  fats  or  compounds  of  fat.  In  animals  they  occur  nor- 
mally in  the  corpus  luteum  ;  in  the  epithelium  of  the  seminal 
vesicles,  testicles,  and  epididymis ;  in  ganglion-cells,  especially 
in  the  sympathetic  nervous  tissue;  and  in  fat  tissue.  Patho- 
logically, such  pigments  are  found  particularly  in  the  muscle- 
cells  in  brown  atrophy  of  the  heart,  and  less  abundantly  in  the 
epithelium  of  atrophied  livers  and  kidneys  (Lubarsch1  and 
Sehrt 2).  All  are  characterized  by  staining  by  such  fat  stains  as 
sudan  III  and  scarlet  R,  and  usually,  but  not  constantly,  by  osmic 
acid ;  they  are  dissolved  by  the  usual  fat  solvents.  It  is  ques- 
tionable if  all  pigments  that  stain  for  fat  should  be  considered  as 
true  lipochromes,  however,  for  their  other  reactions  are  variable. 
Typical  plant  lipochromes,  including  the  pigments  of  Staphyl- 
ococcus  pyogenes  aureus  and  citreus,  are  colored  blue  by  con- 
centrated sulphuric  acid  with  formation  of  small  blue  crystals 
of  lipocyanin.  With  iodin-potassium-iodide  solution  they  are 
colored  green.  Lipochrome  of  frog-fat  stains  blue  with  the  iodin- 
potassium-iodide  solution  (Neumann 3) ;  lipochrome  of  the  cor- 
pus luteum  (called  lutein)  occasionally  gives  a  faint  blue  with 
sulphuric  acid  or  LugoFs  solution  (Sehrt) ;  but  the  fat-holding 
pigments  of  the  other  tissues  mentioned  above  do  not  give 
either  of  these  reactions.  Possibly  these  last  are  not  true  lipo- 
chromes, therefore,  but  rather  pigments  chemically  or  physically 
combined  with  fat.  Cotte 4  believes  that  the  true  lipochromes 
of  plants  and  animals  have  a  cholesterin  base,  but  the  presence 
of  glycerin  in  plant  and  bacterial  lipochromes  can  be  demon- 
strated by  the  acrolein  test — possibly,  therefore,  both  cholesterin 
and  neutral  fats  are  present.  Melanins  and  pigments  derived 
from  hemoglobin  do  not  stain  with  sudan  III  and  are  not  sol- 
uble in  ether,  etc.,  and  hence  can  be  readily  distinguished  from 
the  fatty  pigments. 

The  pigment  that  causes  the  peculiar  green  color  characteristic 
of  certain  malignant  growths,  chloromaf  was  considered  by  Chiari, 
Huber,  and  others  as  a  fatty  substance  related  to  or  identical 

1Cent.  f.  Pathol.,  1902  (13),  881. 
2Virchow's  Arch.,  1904  (177),  248. 
3  Virchow's  Arch.,  1902  (170),  363. 
*Compt.  Rend.  Soc.  Biol.,  1903  (55),  812. 

5  Literature  by  Dock,  Amer.  Jour.  Med.  Sci.,  1893  (106),  152;  and  Dock 
and  Warthin,  Med.  News,  1904  (85),  971. 


400  PATHOLOGICAL  PIGMENTATION 

with  the  lipochromes.  It  commonly  fades  on  exposure  to  air, 
and  also  when  in  the  usual  preservative  fluids,  to  which  it  does 
not  impart  its  color.  It  contains  no  iron,  is  soluble  in  absolute 
alcohol  and  in  ether,  and  is  usually,  but  not  always  (v.  Reck- 
linghausen),  stained  black  with  osmic  acid.  The  pigment  of 
xanthdasma  multiplex  also  seems  to  be  a  fatty  substance  (Poens- 
gen x). 

Chromophile  cells  may  be  considered  in  this  connection.  Kohn 2  has 
described  certain  cells  with  a  decided  affinity  for  chromic  acid  and  its 
salts,  found  abundantly  in  the  sympathetic  nervous  system,  in  the  carotid 
gland,  and  in  the  medulla  of  the  adrenal.  They  are  also  present  in 
tumors  derived  from  these  organs.  Extracts  from  such  organs  have  a 
marked  effect  in  raising  blood  pressure,  and,  according  to  Wiesel,3  they 
are  greatly  involved  in  Addison's  disease.  The  nature  of  the  chromo- 
phile  substance  is  unknown,  but  it  can  only  be  fixed  by  chromic  acid 
or  chromates  ;  cells  hardened  by  other  means  show  merely  spaces  in  the 
places  occupied  by  this  substance.  Mulon 4  believes  it  to  be  the  same 
as  the  adrenalin. 

BLOOD    PIGMENTS5 

Red  corpuscles  behave  much  as  do  other  non-nucleated  frag- 
ments of  cells,  undergoing  disintegration  rapidly  and  constantly 
when  under  normal  conditions,  as  well  as  when  subjected  to 
various  harmful  influences  (see  "  Hemolysis "),  or  when  outside 
of  the  vessels  in  extravasations  of  blood.  The  processes  and 
products  of  their  disintegration  are,  therefore,  much  the  same 
whether  occurring  under  normal  or  pathological  conditions. 
The  hemoglobin  molecule  is  large  and  complex,  and  from  it  are 
derived  many  substances  of  the  nature  of  pigments ;  indeed, 
hemoglobin  itself  may  appear  free  as  a  pigment. 

Hemoglobin  is  a  compound  proteid,  consisting  of  a  proteid 
group  (globin)  and  a  coloring-matter  (hematin  or  hemochromogen). 
The  proteid  globin  is  of  a  basic  nature,  and  seems  allied  to 
the  histons.  The  hematin  is,  therefore,  presumably  acid,  and 
the  compound  proteid,  hemoglobin,  is  strikingly  like  the  nucleo- 
proteids  in  nature.  Hemoglobin  ordinarily  does  not  crystallize 
readily,  especially  the  hemoglobin  of  man,  and  it  is  doubtful  if 
it  ever  does  so  in  the  living  tissues,  although  possibly  this  may 
occur  in  the  center  of  large  hematomas.  In  bodies  that 
have  undergone  postmortem  decomposition,  and  occasionally  in 

1  Virchow's  Arch.,  1883  (91),  354. 
2Prag.  med.  Woch.,  1902  (27),  325. 
3Zeit.  f.  Heilk.,  Path.  Abt,  1903  (24),  257. 
*Compt.  Kend.  Soc.  BioL,  1904  (56),  113. 

5  Literature  by  Schmidt,  Ergebnisse  der  PathoL,  1894  (I2),  101 ;  and  1896 
(III!),  542;  Schulz,  Ergebnisse  der  Physiol.,  1902  (1^,  505. 


BLOOD  PIGMENTS  401 

specimens  kept  for  microscopic  purposes,  irregular  orange-yel- 
low crystalline  masses  of  hemoglobin  may  be  found.  This  occurs 
particularly  if  the  blood  has  been  acted  upon  by  hemolytic 
agents  or  has  undergone  putrefactive  changes,  and  then  is 
hardened  in  alcohol.  The  crystals  are  either  oxyhemoglobin, 
or  more  often  an  isomeric  or  polymeric  modification,  parahemo- 
globin  (Nencki).  Hemoglobin  also  enters  cells  unchanged, 
imparting  a  diffuse  yellowish  color. 

In  the  decomposition  of  hemoglobin  the  first  step  is  the 
splitting  of  the  globin  (which  does  not  form  pigments)  from  the 
hematin,  from  which  many  pigments  may  be  derived. 

Hematin. — The  formula  given  for  this  substance  by  Nencki, 
C32H32N4FeO4,  has  been  generally  accepted,  although  it  is  not 
certain  that  the  hematin  of  all  animals  is  the  same.  It  is  found 
frequently  as  an  amorphous,  dark-brown  or  bluish-black  sub- 
stance, in  large,  old  extravasations  of  blood,  but  seldom  in 
small  hemorrhages.  As  a  pathological  pigment,  however, 
hematin  is  by  no  means  so  frequently  found  as  its  derivatives. 
Wherever  formed  its  duration  is  transient,  for  it  gradually  splits 
up  into  an  iron-free  pigment  (hematoidin)  and  an  iron-containing 
pigment  (hemosiderin).  This  change  may  be  represented  by  the 
following  equation,  according  to  Nencki  and  Sieber l : 

C32H32N404Fe  +  2H20  =  2C16H18N2O3  +  Fe. 
(hematin)  (hematoidin) 

Hematoidin  may  be  found  in  old,  large  extravasations,  as 
orange-colored  or  red  rhombic  plates,  first  described  by  Yirchow. 
Sometimes,  however,  hematoidin  occurs  in  the  form  of  yellowish 
granular  masses.  It  seems  to  be  nearly  or  quite  identical  with 
the  bile-pigment,  bilirubin,  and  it  is  probably  the  source  of  this 
substance  under  normal  conditions.  When  formed  in  excessive 
amounts,  either  through  increased  destruction  of  corpuscles  in 
the  vessels  or  in  extravasations,  the  amount  of  bile-pigment  is 
increased  (see  "  Icterus  ").  Possibly  some  of  the  hematoidin 
becomes  transformed  directly  into  urobilin,  and  is  then  eliminated 
in  the  urine. 

Hemosiderin 2  is  relatively  insoluble,  and,  therefore,  is 
more  slowly  removed  when  formed  in  hemorrhages,  and  more 
abundantly  deposited  in  the  tissues  when  formed  after  excessive 
hemolysis.  According  to  Neumann,  hemosiderin  is  produced 
only  under  the  influence  of  living  cells  and  in  the  presence  of 

1  Arch.  exp.  Path.  u.  Pharm.,  1888  (24),  440. 

2  See  Neumann,  Virchow's  Arch.,  1888  (111),  25;    1900  (161),  422;   1904 
(177)  401  ;  also  Arnold,  ibid.,  1900  (161),  284. 

26 


402  PATHOLOGICAL  PIGMENTATION 

oxygen,  while  hematoidin  arises  independent  of  cellular  activity.1 
Milner 2  considers  that,  under  similar  conditions,  an  iron-con- 
taining pigment  is  also  formed,  which  differs  from  hemosiderin 
in  having  the  iron  so  combined  that  it  cannot  react  with  the 
usual  reagents  ;  this  pigment  may  later  change  into  hemosiderin. 
Up  to  the  present  time  we  do  not  know  the  chemical  nature  of 
hemosiderin,  nor  its  exact  fate  in  the  body,  but  it  is  probably 
utilized  in  the  manufacture  of  new  hemoglobin,  for  it  is  known 
that  the  iron  liberated  when  hematin  is  broken  up  in  the  body 
under  experimental  conditions  is  deposited  and  not  eliminated 
(Morishima 3). 

Unstained  hemosiderin  generally  appears  in  the  form  of  brown 
or  yellowish-brown  granules,  and  not  as  crystals.  After  a  time 
it  is  taken  up  and  deposited  to  a  large  extent  in  the  liver,  spleen, 
bone-marrow,  and  kidney,  either  as  hemosiderin  or  possibly  as 
some  other  iron  compound  of  similar  nature.  From  these  sites 
it  seems  to  be  later  taken  up  to  be  utilized  in  the  manufacture 
of  new  red  corpuscles. 

Hematoporphyrin. — This  substance  is  readily  formed 
from  hematin  through  removal  of  the  iron,  as  shown  by  the 
following  reaction  : 

C32H32N4Fe04  +  2H2O  +  2HBr  =  2C16H18N2O3  +  FeBr2  +  H2. 
(hematin)  (hematoporphyrin) 

The  formation  of  hematoporphyrin  from  hematin  also  occurs 
readily  in  the  animal  body,  provided  that  the  hematin  is  in  a 
reduced  condition,  according  to  Laidlaw,4  but  not  when  oxidized. 

The  structural  formula  is  believed  to  be  as  shown  below : 

CH2  CH2 


HC-C         C(OH)  -  (OH)Cf\  C-CH 

, 

\/ 

Physiologically,  this  pigment  is  of  great  interest,  because  of 
the  close  chemical  relation  that  it  has  been  found  to  bear  to 
chlorophyll, 5  with  which  hemoglobin  is  so  closely  related  func- 
tionally. It  is  also  interesting  to  consider  that  whereas  carniv- 
ora  obtain  much  hemoglobin  in  their  food,  herbivora  obtain 

1  The   accumulation    of    iron  in  the  liver  which  follows    poisoning  with 
hemolytic  agents,  is  not  prevented  or  diminished  by  preliminary  removal  of 
the  spleen  (Meinertz,  Zeit.  exp.  Path.  u.  Ther.,  1906  (2),  602). 

2  Virchow's  Arch.,  1903  (174),  475. 

3  Arch.  exp.  Path.  u.  Pharm.,  1898  (41),  291. 

4  Jour,  of  Physiol.,  1904  (31),  464. 

5  For  literature  see  Abderhalden,  "  Lehrbuch  der  physiol.  Chemie,"  1906. 


BLOOD  PIGMENTS  403 

much  chlorophyll.  Pathologically,  hematoporphyrin  is  of 
interest  as  a  urinary  pigment,  being  found  normally  in  the  urine 
in  traces,  but  present  in  considerable  quantities  in  many  diseases,1 
such  as  rheumatism,  tuberculosis,  various  liver  diseases,  and, 
most  strikingly,  after  the  administration  of  sulphonal  or  trional. 
When  in  abundance  it  may  color  the  urine  a  rich  Burgundy  red. 

Psetldomelanosis. — When  loosely  bound  iron  is  present 
in  the  tissues,  and  in  the  same  tissues  sulphides  are  produced 
through  bacterial  action,  a  discoloration  with  sulphide  of  iron 
will  result,  which  is  called  pseudomelanosis,  because  the  pigment 
resembles  true  melanin  in  its  blackness.  This  is  most  frequently 
observed  as  a  postmortem  phenomenon  in  and  about  the 
abdominal  cavity,  and  in  the  ordinary  postmortem  discoloration 
both  the  liberation  of  the  iron  from  its  firm  organic  combination, 
and  the  production  of  hydrogen  sulphide,  are  the  work  of 
bacteria.  Pseudomelanosis  may  also  occur  intra  vitam,  particu- 
larly in  the  margins  of  infected  areas,  and  it  may  also  be 
observed  in  the  liver  and  spleen,  and  about  the  peritoneum,  in 
bodies  examined  immediately  after  death,  before  any  evident 
postmortem  decomposition  has  set  in.  This  seems  to  depend 
upon  the  previous  intra  vitam  formation  of  hemosiderin,  which 
is  then  combined  by  sulphur  liberated  from  tissue  proteids 
through  bacterial  action.2  If  hydrogen  sulphide  acts  upon 
hemoglobin  that  has  not  been  decomposed,  a  greenish  compound 
of  sulphur-methemoglobin  is  formed  (Harnack3),  which  is  the 
cause  of  the  greenish  color  seen  in  the  abdominal  walls  and 
along  the  vessels  of  cadavers.  This  union  of  hemoglobin  and 
hydrogen  sulphide  occurs  only  when  oxygen  is  present  (oxyhemo- 
globin).  The  sulphur-hemoglobin  compound  is  readily  decom- 
posed by  weak  acids,  even  by  CO2,  with  the  formation  of 
methemoglobin,  which  in  turn  readily  becomes  decomposed  to 
form  hematin. 

Hetnofuscin  is  the  name  given  by  von  Recklinghausen  to 
the  brownish  pigment  found  in  involuntary  muscle-fibers,  par- 
ticularly in  the  wall  of  the  intestine.  It  does  not  react  for 
iron,  and  is  insoluble  in  alcohol,  ether,  chloroform,  or  acids ; 
therefore  it  is  not  a  lipochrome.  von  Recklinghausen,  and  also 
Goebel,4  ascribe  this  pigment  to  an  alteration  of  hemoglobin 
which  enters  the  cells  in  dissolved  form,  but  Rosenfeld,5  who 
has  submitted  the  material  to  analysis  after  isolation,  found 

1  See  Garrod,  Jour,  of  Physiol.,  1892  (13),  598. 

2  Ernst,  Virchow's  Arch.,  1898  (152),  418.     Literature. 
3Zeit.  physiol.  Chem.,  1899  (26),  558. 

4  Virchow's  Arch.,  1894  (136),  482. 

5  Arch.  exp.  Path.  u.  Pharm.,  1900  (45),  46. 


404  PATHOLOGICAL  PIGMENTATION 

3.70  per  cent,  of  sulphur,  from  which  he  considers  that  it  is 
related  to  the  melanins  or  melanoid  substances.  The  substance 
is  readily  dissolved  by  alkalies,  and  contains  no  iron.  Accord- 
ing to  Taranoukhine,1  the  pigment  in  the  myocardium  in 
brown  atrophy  of  the  heart  is  also  derived  from  proteids,  and  is 
neither  a  lipochrome  nor  a  hemoglobin  derivative.  Other 
observers,  however,  consider  this  pigment  a  lipochrome  (q.  v.). 

Hemocliromatosis.2 — This  name  was  given  by  von  Reck- 
linghausen  to  a  condition  in  which  the  organs  and  tissues 
throughout  the  body  are  abundantly  infiltrated  with  two  pig- 
ments :  one,  iron-containing,  identical  with  hemosiderin  ;  the 
other  seems  to  be  the  same  as  the  hemofuscin  described  above. 
The  hemosiderin  is  found  chiefly  in  the  parenchyma  cells  of 
the  glandular  organs,  especially  the  liver  and  pancreas,  which 
organs  usually  show  marked  interstitial  proliferation.  The 
hemofuscin  is  found  in  the  smooth  muscle-fibers  of  the  gastro- 
intestinal tract,  blood-vessels,  and  genito-urinary  tract.  Under 
the  heading  of  local  hemochromatosis,  von  Recklinghausen 
grouped  such  conditions  as  brown  atrophy  of  the  heart,  and 
pigmentation  of  the  intestinal  wall,  which  probably  are  quite 
distinct  from  the  generalized  hemochromatosis,  since  the  local 
form  occurs  as  a  physiological  process  in  old  age.  In  a  con- 
siderable proportion  of  the  cases  of  generalized  hemochroma- 
tosis there  occurs  diabetes,  called  by  Hauot,"  bronzed  diabetes," 
because  of  the  coloration  of  the  skin.3  It  has  been  suggested 
that  the  pigmentation  is  due  to  decomposition  of  the  blood-cor- 
puscles in  the  diabetic  blood,  but  recent  writers  seem  agreed 
that  the  pigmentation  and  sclerotic  changes  precede  the  diabetes, 
which  is  secondary  to  the  atrophic  and  sclerotic  changes  in  the 
pancreas.  There  can  be  little  question  that  both  the  pigment 
formation  and  the  tissue  changes  depend  upon  some  intoxica- 
tion, the  origin  and  nature  of  the  toxic  agent  being  entirely 
unknown.  In  many  cases  it  has  seemed  probable  that  alcohol 
might  have  been  the  inciting  cause. 

Opie's  conclusions  concerning  this  subject  are  as  follows  :  (1) 
There  is  a  distinct  morbid  entity,  hemochromatosis,  character- 
ized by  wide-spread  deposition  of  an  iron-containing  pigment  in 
certain  cells,  and  an  associated  formation  of  iron-free  pigments 
in  a  variety  of  localities  in  which  pigment  is  found  in  moderate 

1  Koussky  Arch.  Patol.,  1900  (10)  441. 

2  Literature  given  by  Opie,  Jour.  Exp.  Med.,  1899  (4),  279 ;  and  Beattie, 
Jour.  Pathol.  and  Back,  1903  (9),  117. 

3  Literature  by  Opie  and  Beattie  (loc.  ait.)  ;  also  by  Anschiitz,  Deut.  Arch, 
klin.  Med.,  1899  (62),  411;  Hess  and  Zurhelle,  Zeit.  klin.  Med.,  1905  (57), 
362. 


ICTERUS  405 

amount  under  physiological  conditions.  (2)  With  the  pigment 
accumulation  there  occur  degeneration  and  death  of  the  contain- 
ing cells  and  consequent  interstitial  inflammation,  notably  of 
the  liver  and  pancreas,  which  become  the  seat  of  inflammatory 
changes  accompanied  by  hypertrophy  of  the  organ.  (3)  When 
chronic  interstitial  pancreatitis  has  reached  a  certain  grade  of 
intensity,  diabetes  ensues,  and  is  the  terminal  event  in  the 
disease. 

ICTERUS1 

Pigmentation  of  the  tissues  of  the  body  in  jaundice  depends 
upon  the  presence  in  them  of  bile-pigments,  which  have  been 
formed  in  the  liver  and  reabsorbed  either  into  the  lymph  or 
blood  (or  both).  Although  a  pigment  that  seems  to  be  chem- 
ically identical  with  bilirubin  (hematoidin)  may  be  formed  from 
hemoglobin  liberated  on  the  breaking  up  of  red  corpuscles,  yet 
this  is  probably  never  formed  in  sufficient  amounts  outside  of 
the  liver  to  give  rise  to  general  icterus.  However,  the  local 
greenish-yellow  pigmentation  occurring  in  the  vicinity  of  extrav- 
asations of  blood,  due  to  hematoidin  formation,  may  be  looked 
upon  as  a  "  local  jaundice." 

Bile-pigments. — Bilirubin  is  of  a  reddish-yellow  color,  and  it  is 
the  chief  pigment  of  human  bile.  Its  formula  is  C16H18N2O3,  and  its 
relation  to  hematin,  from  which  it  is  formed,  is  shown  by  the  following 
formula,  which,  according  to  Nencki  and  Sieber,  expresses  the  manner 
in  which  blood  pigment  is  converted  into  bilirubin  by  the  liver  under 
normal  conditions,  and  into  hematoidin  (its  isomer)  in  the  tissues  and 
fluids  of  the  body  in  pathological  conditions  : 

C32H32N404Fe  +  2H20  -=  2C16H18N2O3  +  Fe. 
(hematin)  (hematoidin  or  bilirubin) 

Bilirubin  is  not  soluble  in  water,  but  dissolves  in  the  alkaline  body 
fluids  as  a  soluble  compound,  "bilirubin  alkali."  It  is  very  slightly 
soluble  in  ether,  benzene,  carbon  disulphide,  amyl-alcohol,  fatty  oils, 
and  glycerin,  but  is  more  soluble  in  alcohol  and  in  chloroform. 

Biliverdin,  C16H18N2O4,  as  its  formula  indicates,  is  an  oxidation 
product  of  bilirubin.  Bilirubin  in  alkaline  solutions  will  oxidize  into 
biliverdin  merely  on  exposure  to  the  air,  and  the  change  from  yellow  to 
green  of  icteric  specimens  when  placed  in  oxidizing  solutions  (e.  g., 
dichromate  hardening  fluids)  is  due  to  the  formation  of  the  green  bili- 
verdin. Biliverdin  is  the  chief  pigment  of  the  bile  of  carnivora,  but  it 
is  also  present  in  varying  amounts  in  human  bile. 

The  various  other  biliary  pigments,  namely,  bilifuscin,  biliprasin, 
choleprasin*  bilihumin,  and  bilicyanin,  are  probably  not  normal  constit- 
uents of  bile,  but  are  oxidation  products  of  bilirubin,  and  are  found 

1  Literature  by   Stadelmann,  "  Der  Icterus,"  Stuttgart,  1891 ;    Minkowski, 
Ergebnisse  der  Pathol.,  1895  (2),  679. 

2  See  Kiister,  Zeit.  physiol.  Chem.,  1906  (47),  294. 


406  PATHOLOGICAL  PIGMENTATION 

chiefly  in  gall-stones  (q.  v.).  A  pigment  similar  to  urobilin  may  be 
present  in  normal  bile.  The  total  amount  of  pigments  present  in  bile 
is  probably  not  far  from  one  gram  per  liter ;  rather  under  than  above 
this  amount. 

Etiology  of  Icterus. — Although  hematoidin,  which  is 
isomeric  if  not  indentical  with  bilirubin,  may  be  formed  outside 
of  the  liver  when  red  corpuscles  are  broken  up  in  hemorrhagic 
extravasations,  and  possibly  also  when  they  are  broken  up 
within  the  vessels  by  hemolytic  agents,  yet  it  is  generally  con- 
sidered that  a  true  general  icterus  does  not  occur  without  the  liver 
being  implicated.  This  view  rests  on  evidence  of  various  sorts. 
First,  the  classical  experiments  of  Minkowski  and  Naunyn,1 
which  demonstrated  that  in  geese  the  production  of  hemolysis 
by  means  of  arseniuretted  hydrogen  leads  to  icterus,  but  if  the 
livers  of  the  geese  have  been  previously  removed,  no  icterus  fol- 
lows the  poisoning.  Second,  the  repeated  demonstration  that 
in  icterus  produced  by  septic  conditions,  poisoning,  etc.,  which 
was  formerly  looked  upon  as  a  "  hematogenous  "  icterus,  the 
urine  contains  bile  salts  as  well  as  pigment,  indicating  an  absorp- 
tion of  bile  from  the  liver.  Third,  the  finding  of  histological 
evidence  that  in  so-called  hematogenous  icterus  there  occur 
occlusions  or  lesions  of  some  sort  in  the  bile  capillaries,  which 
can  account  for  the  reabsorption  of  the  bile  into  the  general  cir- 
culation.2 Joannovics3  gives,  as  a  result  of  a  comparative 
study  of  icterus  from  bile  obstruction  and  icterus  from  hemol- 
ysis, the  following  chief  differences :  Icterus  due  to  hemolysis 
appears  sooner  than  icterus  from  bile-duct  occlusion,  and  reaches 
a  much  higher  degree ;  the  obstruction  in  hemolytic  icterus  is 
intra-acinous  ;  in  stasis  it  is  chiefly  inter-acinous ;  in  hemolytic 
icterus  there  is  a  large  splenic  tumor  due  to  accumulation  of 
degenerated  red  cells  in  the  spleen,  where  they  become  disin- 
tegrated preliminary  to  the  formation  of  bile-pigment.  If  the 
spleen  is  removed,  hemolytic  agents  do  not  cause  icterus,  because 
the  corpuscles  are  not  then  prepared  for  pigment  formation. 

Therefore,  it  is  believed  that  the  pigments  that  produce  the 
general  discoloration  of  icterus  are,  at  least  for  the  most  part, 
manufactured  by  the  liver,  whatever  the  cause  of  the  reabsorp- 
tion of  the  bile  from  the  liver  into  the  blood  may  be.  That 

1  Arch.  f.  exp.  Pathol.  u.  Pharm.,  1886  (21),  1. 

2  See  Eppinger,  Ziegler's  Beitr.,  1903  (33),  123;  Gerhardt,  Munch,  med. 
Woch.,  1905  (52),  889.     Lang  (Zeit.  exp.  Path.  u.  Ther.,  July,  1906,  Bd.  3) 
has  demonstrated  the  presence  of  fibrinogen  in  the  bile  in  phosphorus- poison- 
ing, which  perhaps  accounts  for  the  "  bile  thrombi "  observed  by  Eppinger  in 
toxic  icterus. 

3  Zeit.  f.  Heilk.,  Path.  Abt.,  1904  (25),  25. 


ICTERUS  407 

hemolytic  agents  cause  icterus  is  explained  by  the  fact  that 
on  account  of  the  large  amounts  of  free  hemoglobin  brought  to 
the  liver,  excessive  amounts  of  bile-pigment  are  formed,  which 
render  the  bile  so  viscid  that  it  blocks  up  the  fine  bile  capillaries  ; 
on  account  of  the  low  pressure  at  which  bile  is  secreted,  a  slight 
obstruction  of  this  kind  is  sufficient  to  stop  entirely  the  outflow 
of  bile,  which  then  enters  the  lymphatics  of  the  liver  and  also 
the  blood-stream  itself.1  It  is  also  possible  that  the  hemolytic 
poisons  injure  the  liver-cells  so  much  that  the  minute  intra-  and 
intercellular  bile  capillaries  become  disorganized,  and  permit  of 
escape  of  bile  into  the  lymph-spaces  and  its  absorption  into  the 
blood-vessels.  Swelling  of  the  degenerated  liver-cells  may  also 
be  an  important  factor  in  the  occlusion  of  the  bile  capillaries, 
and  swelling  of  the  living  cells  of  the  bile  capillaries  may  also 
coexist. 

Toxicity  of  Bile. — In  any  event,  we  must  appreciate  that 
in  icterus  not  only  are  abnormally  large  quantities  of  bile-pig- 
ment present  in  the  blood,  but  also  the  other  less  conspicuous 
constituents  of  the  bile.  The  relative  toxicity  of  the  bile-pig- 
ments and  the  bile  salts  is  not  as  yet  uniformly  agreed  upon. 

Bile=pigments. — Bouchard2  and  others  have  claimed  that 
the  bile-pigments  are  far  more  toxic  than  the  bile  salts,  which 
is  contradicted  by  Rywosch  and  others.  As  Rywosch  found 
that  doses  of  0.6  gram  of  bile-pigments  per  kilo  had  almost  no 
effect  on  rabbits,  it  is  doubtful  if  the  amount  absorbed  by  a 
patient  with  icterus  can  have  serious  effects,  since  it  is  estimated 
that  the  normal  daily  excretion  of  bile-pigment  in  man  averages 
but  about  0.5  gram.  The  amount  of  pigment  in  the  blood  in 
icterus  is  correspondingly  minute.3 

Bile  salts  are  undoubtedly  toxic,  generally  producing  depres- 
sion of  the  central  nervous  system,  with  resulting  coma  and 
paralysis ;  they  are  also  decidedly  toxic  to  cells  of  all  sorts, 
causing  hemolysis  and  marked  destruction  of  tissue-cells.  Small 
quantities  of  bile  salts  stimulate  the  central  end  of  the  vagus, 
and  larger  amounts  influence  the  heart  itself;  hence  in  icterus 
we  observe  a  slowing,  and  often  an  irregularity,  of  the  pulse, 
and  the  blood  pressure  is  lowered.  Although  there  has  been 

1  See  Mendel  and  Underbill,  Amer.  Jour.  Physiol.,  1905  (14),  252. 

2  Literature  and  discussion  by  Stadelmann,  Zeit.  f.  Biol.,  1896  (34),  57. 

3  A  series  of  analyses  by  Gilbert  and  others  (Compt.  Kend.  Soc.  Biol.,  1905 
(38),  July  7,  et  seq.)  gave  the  following  results:  Normal  blood-serum  contains 
0.027-0.08  gram  bilirubin  per  liter,  which  is  the  source  of  the  normally  pro- 
duced urobilin ;  in  obstructive  icterus  they  found  0.068  gram  of  bilirubin  per 
liter,  or  about  0.2  gram  in  the  blood  of  the  entire  body  ;  in  biliary  cirrhosis 
0.33  gram  per  liter,  in  icterus  neonatorum  0.2  to  0.5  gram,  in  pneumonia  0.068 
gram  was  found. 


408  PATHOLOGICAL  PIGMENTATION 

much  dispute  as  to  whether  the  chief  effects  of  icterus  upon  the 
heart  depend  upon  action  of  the  bile  salts  upon  the  vagus,  or 
upon  the  intracardiac  ganglia,  or  upon  the  muscle  itself/  yet 
Weintraud  demonstrated  that  in  some  cases  of  icterus  adminis- 
tration of  atropin,  which  paralyzes  the  vagus,  stops  the  brady- 
cardia,  indicating  the  importance  of  the  effects  of  the  bile  salts 
upon  the  vagus  in  causing  this  feature  of  cholemia.  According 
to  Meltzer  and  Salant,2  bile  also  contains  a  tetanic  element,  which 
disappears  from  stagnating  bile;  the  bile  salts  contain  this 
tetanizing  agent  in  less  amount  than  does  the  whole  bile. 

Since  the  bile  salts  cause  hemolysis,  and  since  in  even 
"hematogenous"  jaundice  they  enter  the  blood,  it  can  readily 
be  seen  that  in  this  way  an  increased  formation  of  bile-pigment 
may  be  incited  which  leads  to  further  obstruction  to  the  outflow 
of  bile  from  the  liver,  and  a  "vicious  circle "  may  thus  be 
established.  The  necroses  observed  in  the  liver  in  icterus, 
"  icteric  necrosis,"  are  generally  ascribed  to  the  cytotoxic  effects 
of  the  bile  salts,  although  it  is  difficult  always  to  eliminate 
infection  extending  along  the  bile-ducts  to  the  liver  tissue.  The 
itching  and  irritation  of  the  skin  in  icterus  may  be  due  to  the 
effect  of  the  bile-pigments  deposited  in  it. 

A  remarkable  tendency  to  spontaneous  hemorrhages,  frequently 
observed  in  icterus,  probably  depends  upon  injury  to  the  capil- 
lary endothelium  by  the  bile  salts  ;  while  the  protracted,  often 
uncontrollable,  hemorrhage  that  may  occur  from  operation 
wounds  in  icteric  patients,  is  related  to  the  slowed  coagulation 
of  the  blood  observed  in  icterus.  The  cytotoxic  effect  of  the 
bile  salts  is  also  shown  by  the  albuminuria  of  icteric  persons, 
which  frequently  results  from  the  renal  lesions  the  bile  pro- 
duces. 

Croftan 3  summarizes  the  physiological  effects  of  bile  acids  as 
follows  :  (1)  A  powerful  cytolytic  action,  affecting  both  blood- 
corpuscles  and  tissue-cells.  (2)  A  distinct  cholagogue  action. 
§3)  In  small  doses  (1-500)  they  aid  coagulation.  (4)  In  large 
oses  (1—250  and  over)  they  retard  coagulation.  (5)  Slow 
the  heart  action.  (6)  In  small  doses  they  act  as  vasodilators ; 
in  large  doses,  as  vasoconstrictors.  (7)  Reduce  motor  and 
sensory  irritability.  (8)  Act  on  the  higher  cerebral  centers, 
causing  coma,  stupor,  and  death. 

JSee  Minkowski,  Ergeb.  der  Pathol.,  1895  (2),  709. 

2  Jour.  Exp.  Med.,  1906  (8),  128;  review  and  literature  concerning  toxic- 
ity  of  bile. 

3  New  York  Med.  Jour.,  1906   (83),  810 ;  see  also  Faust,  "  Die  tierische 
Gifte,"  Braunschweig,  1906,  p.  29. 


ICTERUS  409 

It  is  difficult  to  decide  how  much  of  the  profound  intoxica- 
tion that  is  sometimes  present  in  icterus  ("cholemia"  and 
"  icterus  gravis ")  to  ascribe  to  the  reabsorbed  bile,  for  fre- 
quently there  is  an  accompanying  infection,  and  even  if  there 
is  no  infection  the  impairment  of  liver  function  by  the  obstruc- 
tion to  bile  outflow  must  also  be  reckoned  with.  The  liver  is 
not  only  the  great  destroyer  of  toxic  substances  absorbed  from 
the  alimentary  canal,  but  it  is  also  an  important  seat  of  nitrog- 
enous metabolism,  interference  with  which  may  lead  to  ac- 
cumulation of  many  toxic  nitrogenous  substances  in  the  blood.1 
The  long  duration  of  severe  icterus  in  some  cases  of  occlusion 
of  the  bile-ducts,  with  relatively  slight  evidences  of  intoxication, 
would  seem  to  indicate,  however,  that  on  the  whole  the  bile  is 
not  so  much  responsible  for  the  intoxication  observed  in  icterus 
as  are  the  associated  conditions.  On  the  other  hand,  in  not  a 
few  instances  it  has  been  observed  that  escape  of  large  quanti- 
ties of  bile  into  the  peritoneal  cavity  may  be  followed  by  symp- 
toms similar  to  those  of  icterus  gravis ;  in  these  cases  only  the 
bile  can  be  held  responsible  for  the  intoxication.2 

The  Pigmentation  in  Icterus. — Living  tissues  have 
but  a  slight  tendency  to  take  up  bile-pigments,  much  of  the 
tissue-staining  observed  at  autopsy  being  due  to  postmortem 
imbibition  from  the  blood  and  lymph.  Quincke 3  found  that 
after  subcutaneous  injection  of  bilirubin  only  the  connective 
tissue,  both  cells  and  intercellular  fibrils,  becomes  diffusely 
colored ;  later,  it  fades  out  of  the  cells,  leaving  only  the  fibrils 
stained.  Muscle-cells,  fat-cells,  and  vessel-walls  take  up  the 
pigment  only  after  their  death.  If  the  jaundice  continues  for 
a  long  time,  the  subcutaneous  deposits  of  bilirubin  may  undergo 
a  slow  oxidation,  the  color  changing  to  an  olive  or  to  a  dirty 
grayish  green.  The  pigment  in  the  connective  tissues  is  at 
first  in  solution,  but  may  be  deposited  in  a  granular  form  after 
a  considerable  amount  has  accumulated. 

The  question  whether  in  icterus  the  skin  may  be  colored  by 
other  pigments  than  bilirubin,  especially  by  its  reduction  prod- 
uct, hydrobilirubin  or  urobilin,  seems  to  have  been  decided 
negatively.  This  substance  is  formed  from  bilirubin  by  bac- 
terial reduction  in  the  intestines,  is  absorbed,  and  is  probably 
the  source  of  the  urobilin  in  the  urine.  No  matter  how  much 
hydrobilirubin  is  produced  in  the  intestine,  however,  or  how 

1  See  Bickel,  Exper.  Untersuch.  iiber  der  Pathol.  der  Cholaemie,  Wiesbaden, 
1900. 

2  See  Ehrhardt,  Arch.  klin.  Chir.,  1901  (64),  314. 

3  Virchow's  Arch.,  1884  (95),  125. 


410  PATHOLOGICAL  PIGMENTATION 

much  urobilin  is  present  in  the  urine,  the  tissues  do  not  become 
pigmented  by  them.  Bile-pigment  is  probably  not  absorbed  as 
such  from  the  intestine  in  sufficient  quantity  to  cause  icterus. 
Such  bile -pigment  as  enters  the  blood  from  the  liver  is  excreted 
through  the  kidneys  chiefly,  but  also  in  the  sweat.  Ordinarily, 
other  secretions  (milk,  tears,  saliva,  sputum)  are  not  colored  in 
jaundice,  but  if  the  secretions  are  mixed  with  inflammatory 
exudations,  they  may  then  be  colored  (e.  g.,  pneumonic  sputum). 
When  the  bile-pigment  is  resorbed  from  the  skin,  it  is  at  least 
in  part  transformed  into  urobilin,  which  appears  in  the  urine  in 
increased  amounts  during  the  period  of  recovery  from  jaundice. 
Part  of  the  bile-pigment  is  probably  eliminated  by  the  liver 
after  the  cause  of  obstruction  has  been  removed  from  the  bile- 
passages. 

Digestive  Disturbances  in  Obstructive  Icterus. — In  case  the 
icterus  depends  upon  the  occlusion  of  the  main  bile-passages  by  stones, 
tumors,  etc.,  the  situation  is  complicated  by  the  effects  of  the  absence 
of  this  natural  secretion  in  the  intestinal  canal.  Carbohydrate  and  pro- 
teid  digestion  seem  to  be  but  little  affected,  especially  the  former,  but 
the  proportion  of  the  ingested  fat  that  appears  in  the  feces  increases  from 
the  normal  7-11  per  cent,  to  60-80  per  cent.  The  products  of  bacterial 
decomposition  of  the  undigested  fat  may  lead  to  injury  of  the  intestinal 
wall  and  disturbance  of  its  function.  Failure  of  absorption  of  fat  also 
favors  intestinal  putrefaction  by  enveloping  the  proteid  substances  so 
that  they  are  not  readily  digested  and  absorbed.  The  relation  of  bile  to 
intestinal  putrefaction  is  still  not  exactly  determined.  Frequently,  but 
by  no  means  always,  there  is  an  increased  intestinal  putrefaction  which 
may  result  in  diarrhea  and  the  appearance  of  excessive  quantities  of 
indican  and  phenol  in  the  urine.  The  idea  once  held  that  the  bile 
salts  acted  as  intestinal  antiseptics  has  not  been  established  by  experi- 
mental investigations  ;  however,  it  is  possible  that  through  their  func- 
tion as  natural  cathartics,  by  stimulation  of  peristalsis,  they  prevent 
stagnation  and  putrefaction  of  proteids. 


CHAPTEE    XVII 

THE  CHEMISTRY  OF  TUMORS 

CHEMICAL  investigations  of  tumors  have  been  relatively  few 
in  number,  but,  so  far  as  they  have  yet  been  made,  there  has 
been  little  detected  that  indicates  any  important  deviation  of 
the  chemical  processes  of  tumors  from  those  of  normal  cells  of 
similar  origin.  Likewise,  the  chemical  composition  of  tumor 
tissue  resembles  closely,  on  the  whole,  the  composition  of  related 
normal  tissues.  It  is  hardly  to  be  imagined  that  the  course  of 
chemical  changes  is  greatly  different  in  tumor  cells  from  that  in 
normal  cells,  in  view  of  the  abundant  evidence  that  the  meta- 
bolic products  of  tumor  cells  are  identical  with  those  of  the  cells 
from  which  they  arose.  Thus,  inetastatic  growths  of  thyroid 
tissue  will  produce  thyroiodin  in  any  part  of  the  body,  liver 
carcinoma  metastases  produce  bile,  tumors  from  the  choroid  or 
from  pigmented  moles  produce  melanin,  etc.  The  capacity  of 
tumor  cells  to  produce  complicated  products  of  metabolic  action 
specific  for  the  parent  cells  from  which  they  arose,  as  illustrated 
above,  indicates  beyond  question  that  the  course  of  their  chem- 
ical activities  is  very  much  like  that  of  normal  cells.  So,  too, 
the  composition  of  the  cells  is  found  to  be  similar  indeed  to  that 
of  the  parent  cells,  both  in  regard  to  primary  and  secondary 
constituents.  Thus,  Bang  found  that  sarcomas  derived  from 
lymph-glands  contain  the  particular  nucleoproteids  that  are  found 
normally  only  in  lymph-glands  ;  hypernephromas  contain,  like 
adrenal  tissue,  much  fat,  lecithin,  and  cholesterin  ;  squamous 
cell  carcinomas  develop  great  amounts  of  kerato-hyalin  ;  carcino- 
mas of  mucous  membranes  may  contain  much  mucin,  etc. 

Many  have  sought  in  cancer  tissues  a  poison  that  might 
account  for  the  cachexia  charateristic  of  new-growths.  Extracts 
have  been  obtained  that  were  destructive  to  red  corpuscles 
(hemolytic),  and  that  were  sometimes  slightly  toxic  to  animals, 
but  the  results  have  not  seemed  sufficiently  striking  to  account 
for  the  appearance  of  cachexia.  Because  of  the  interference 
with  circulation,  brought  about  in  tumors  by  pressure  of  the 
growing  tissues  upon  their  blood-vessels,  areas  of  necrosis  fre- 
quently develop,  and  these,  undergoing  autolysis,  yield  substances 

411 


412  THE  CHEMISTRY  OF  TUMORS 

that  are  hemolytic  and  toxic.1  Whether  these  are  the  cause  of 
cancer  cachexia,  however,  may  be  questioned;  but  they  are 
sufficient  to  account  for  most  of  the  experimental  results  as 
yet  obtained.  No  substance  has  yet  been  isolated  from  or 
detected  in  malignant  growths  that  is  peculiar  to  them  and  not 
found  in  normal  cells,  and  still  less  has  any  substance  been 
detected  that  accounts  in  any  way  either  for  the  occurrence  of 
tumors  or  for  the  effects  that  they  produce. 

Nevertheless,  numerous  observations  have  been  made  con- 
cerning the  chemistry  of  tumors,  which,  although  they  do  not 
as  yet  throw  any  important  light  on  the  fundamental  problems 
of  tumor  pathology,  are  of  much  interest.  These  may  be  briefly 
summarized  as  follows : 

A.  CHEMISTRY  OF  TUMORS  IN  GENERAL 

(1)  Proteids. — Earlier  studies  showed  that  tumor  growths 
contain  the  same  sorts  of  proteids  as  do  normal  tissues,  and 
apparently  in  about  the  same  proportions.  Recently  investiga- 
tions have  been  made  concerning  the  more  minute  chemical 
features.  Wolff2  has  studied  the  proteids  obtained  in  the  juice 
expressed  from  cancer-cells  by  the  Buchner  press.  In  normal 
tissues  such  cell-juice  contains,  almost  constantly,  nearly  equal 
proportions  of  albumin  and  globulin.  In  carcinoma,  how- 
ever, the  albumin  is  usually  three  or  more  times  as  abundant 
as  is  the  globulin.  Of  the  globulins,  it  is  particularly  the 
euglobulin  that  is  reduced,  in  some  instances  being  nearly 
absent.  In  tumor-free  liver  tissue  between  carcinomatous 
growths  the  proportion  of  albumin  was  found  increased  above 
that  normal  for  liver  tissue.  Wolff  found  no  qualitative  dif- 
ferences between  cancer  proteids  and  normal  cell  proteids. 
Joachim  has  found,  similarly,  that  in  cancerous  ascites  the  pro- 
portion of  albumin  is  much  higher  than  in  ascites  from  other 
causes.  This  is  rather  remarkable,  in  view  of  the  fact  that  in 
cachexia  the  proportion  of  albumin  in  the  blood  and  in  exudates 
sinks  much  more  rapidly  than  does  the  proportion  of  globulin.3 

In  all  probability  the  nucleoproteids  of  tumors  share  the  spe- 
cific characteristics  of  the  nucleoproteids  of  the  tissues  from 
which  they  arise — at  least  this  is  the  case  with  the  nucleoproteids 
of  lymphosarcoma,  according  to  Bang.4  The  characteristic  con- 

1Kiilf  (Zeit.  f.  Krebsforschung,  1906  (4),  417)  considers  the  proteolytic 
enzymes  of  much  importance  in  the  causation  of  cancer  cachexia. 

2  Zeitschrift  f.  Krebsforschung.  1905  (3),  95 :  Medizinische  Klinik,  1905  (1), 
13. 

3  Umber,  Zeit.  klin.  Med.,  1903  (48),  364. 
*  Hofmeister's  Beitr.,  1903  (4),  368. 


CHEMISTRY  OF  TUMORS  IN  GENERAL  413 

stituent  of  lymph-glands,  spleen,  and  thymus  is  a  compound  of 
nucleic  acid  and  histon  (histon  nudeinate).  If  to  a  watery  extract 
of  an  organ  a  few  drops  of  CaCl2  solution  are  added,  the  forma- 
tion of  a  precipitate  indicates  the  presence  of  a  lymphatic  tissue. 
If  this  precipitate  is  soluble  in  1  per  cent.  NaCl,  it  is  a  nuclein- 
ate  corresponding  in  type  to  that  of  the  lymph-glands  and  spleen  ; 
if  not  soluble,  it  is  of  the  type  of  the  thymus  or  leucocytes. 
Extracts  from  no  other  organs  give  a  precipitate  with  calcium 
chloride.  Spindle-cell  sarcomas  were  found  not  to  give  this 
reaction,  but  round-cell  sarcomas  of  lymphatic  origin  do,  for 
they  contain  the  specific  nucleinate  abundantly.  Bang  believes 
that  this  reaction  can  be  used  to  distinguish  sarcoma  arising 
from  lymphoid  tissue.  This  seems  to  have  been  confirmed  by 
Beebe,1  who  found  nucleo-histon  only  in  lymph-gland  tissue, 
but  the  distinction  between  thymus  and  lymph-gland  nucleo- 
histon  is  probably  not  so  easily  made  as  Bang  intimates. 

Because  of  their  richly  cellular  structure,  cancers  may  con- 
tain more  nucleoproteid  than  the  tissues  from  which  they  arise. 
Thus  Petry 2  found  50  per  cent,  of  nucleoproteid  in  carcinoma 
of  the  mammary  gland,  as  against  30  per  cent,  in  normal 
tissue. 

Bergell  and  Dorpinghaus 3  have  studied  the  nature  of  the 
proteids  in  tumors  by  determining  the  proportion  of  the  various 
amino-acids  that  compose  them.  Because  of  the  amount  of 
material  necessary  for  the  ester  method,  they  were  obliged  to 
use  a  mixture  of  various  primary  and  secondary  cancers  and 
one  sarcoma.  The  proteid  of  this  tumor-mixture  was  character- 
ized by  the  very  high  proportion  of  alanin,  glutaminic  acid, 
phenylalaniu,  and  asparaginic  acid,  there  being  from  5  to  10  per 
cent,  of  each.  Leucin  was  very  low,  5-10  per  cent,  as  against 
20  per  cent.,  or  higher,  found  in  most  normal  tissues.  Gly- 
cocoll  and  tyrosin  were  present  in  small  quantities,  and  serin 
was  probably  also  present.  Neuberg 4  found  in  cancer  proteid 
1.3  per  cent,  of  tyrosin,  17  per  cent,  of  leucin,  scarcely  1  per 
cent,  of  glutaminic  acid,  and  4.92  per  cent,  of  glycocoll. 
Further  investigations  along  these  lines  are  greatly  to  be 
desired. 

On  account  of  the  amount  of  autolysis  going  on  in  tumors 
the  products  of  proteid  splitting  are  usually  present.  Beebe5 

1  Amer.  Jour.  Physiol.,  1905  (13),  341. 
2Zeit.  physiol.  Chem.,  1899  (27),  398. 
sDeut.  med.  Woch.,  1905  (31),  1426. 

4  Arb.  a.  d.  Path.  Inst.  zu  Berlin,  1906,  p.  593. 

5  Amer.  Jour.  Physiol.,  1904  (11),  139. 


414  THE  CHEMISTRY  OF  TUMORS 

found  in  a  number  of  tumors  leucin,  tyrosin,  tryptophan,  pro- 
teoses  (biuret  reaction),  and  in  one  glycocoll.  Because  of  the 
deficient  circulation  in  the  tumors,  the  ammo-acids  accumulate 
in  the  cancer  tissues  in  sufficient  amounts  to  be  detected,  and 
may  be  found  even  when  no  macroscopic  evidences  of  degen- 
eration are  present.  Possibly  on  account  of  this  poor  absorption 
no  proteoses,  peptones,  or  amino-acids  could  be  found  in  the 
urine  of  cancer  patients  by  Wolff;1  but  Ury  and  Lilienthal2 
found  a  positive  reaction  for  albumose  in  the  urine  in  about  two- 
thirds  of  all  carcinoma  cases  examined  by  them ;  however,  it 
may  be  absent  even  in  advanced  stages.  Petry 3  states  that  in 
normal  mammary  glands  all  the  nitrogen  is  in  a  coagulable 
form,  whereas  in  sarcoma  but  13  per  cent,  is  coagulable.  This 
non-coagulable  nitrogen  is  partly  in  the  form  of  proteoses  and 
peptones,  partly  as  substances  not  giving  the  biuret  reaction. 

(2)  Other  Organic  Constituents. — These,  in  general, 
resemble  the  organic  constituents  of  the  tissue  from  which  the 
tumor  arises,  for  a  structural  resemblance  to  the  parent  tissue 
always  exists,  and  as  structural  features  depend  largely  on  the 
proportion  of  the  chemical  components,  a  structural  similarity 
fairly  implies  a  chemical  similarity.  For  example,  adrenal 
tissue  contains  much  fatty  material,  especially  lecithin  and  cho- 
lesterin,  and  hypernephromas  show  a  similar  composition ;  Gatti 4 
noted  that  the  proportion  of  lecithin  in  a  hypernephroma  is 
similar  to  that  in  the  adrenal ;  the  fat  of  a  lipoma  is,  in  its 
qualitative  features,  almost  identical  with  the  normal  fat  of  the 
same  individual ;  tumor  melanin  shows  no  characteristic  chem- 
ical distinction  from  normal  melanin,  etc. 

Glycogen  has  been  particularly  studied  in  tumors,  especially 
because  of  the  erroneous  idea  advanced  by  Brault  that  the  quan- 
tity of  glycogen  is  in  direct  proportion  to  the  malignancy.  From 
a  summary  of  all  the  evidence,  it  seems  that  two  chief  factors 
determine  the  presence  and  amount  of  glycogen  in  tumors. 
One  is  the  embryonic  origin  of  the  tumors ;  thus  tumors  of 
cartilage,  striated  muscle,  or  of  squamous  epithelium,  which 
tissues  normally  contain  much  glycogen,  are  likewise  provided 
with  an  abundance  of  this  material.  Second,  the  occurrence  of 
areas  of  impaired  cell-nutrition  favors  the  accumulation  of 
glycogen  in  the  degenerating  tumor-cells,  just  as  it  leads  to  a 
similar  accumulation  in  all  other  tissues  (Gierke 5).  The  most 
extensive  consideration  of  this  topic  is  reported  by  Lubarsch,6 

1  Zeit.  f.  Krebsforschung,  1905  (3),  95.     *  Virch.  Arch.,  1897  (150),  417. 

2  Arch.  f.  Verdauungskr.,  1905  (11),  72.    5  Ziegler's  Beitr.,  1905  (37),  502. 

3  Loc.  tit.  6  Virchow's  Arch.,  1906  (183),  188. 


CARBOHYDRATES  AND  INORGANIC  CONSTITUENTS  415 

who  found  glycogen  microscopically  in  447  (or  29  per  cent.)  of 
1544  tumors  examined.  It  was  present  in  but  3  out  of  184 
fibromas,  osteomas,  gliomas,  hemangiomas,  lipomas,  and  lymph- 
angiomas,  and  in  but  2  out  of  260  adenomas  from  various 
parts  of  the  body.  It  occurred  in  all  teratomas,  rhabdomy- 
omas,  hypernephromas,  and  syncytiomas.  In  138  sarcomas 
glycogen  was  present  in  70  (50.7  per  cent.);  of  415  carcino- 
mas it  was  found  in  181  (43.6  per  cent.).  In  the  squamous 
epithelial  cancers  70  per  cent,  contained  glycogen,  while  the 
mucoid  or  colloid  cancers  were  always  free  from  glycogen. 
The  glycogen  undoubtedly  enters  the  cells  from  without,  prob- 
ably entering  as  sugar,  and  being  converted  into  glycogen  by 
intracellular  enzymes.  We  have  no  reliable  studies  of  the  actual 
quantity  of  glycogen  in  various  tumors,  although  Meillere1 
states  that  the  microscopic  and  chemical  examination  of  tumors 
give  corresponding  comparative  results,  which  Gierke  states  is 
generally  true  with  glycogen  estimations. 

Pentoses.  —  Neuberg  2  reports  finding,  as  a  product  of  autol- 
ysis  of  a  carcinoma  of  the  liver,  a  pentose  which  was  not  pro- 
duced by  autolysis  of  either  normal  liver  tissue  or  the  primary 
growth  in  the  stomach.  Beebe3  found  that  in  carcinoma  of 
the  mammary  gland  the  percentage  of  pentose  (xylose)  is  some- 
what higher  than  the  amount  in  normal  mammary  glands 
(about  0.23  per  cent.).  Carcinoma  in  the  liver  did  not  show 
any  constant  excess  of  pentose  above  that  of  normal  liver  tissue 
(about  0.38  per  cent.).  A  primary  carcinoma  of  the  liver 
showed  quite  the  same  pentose  and  phosphorus  content  as  nor- 
mal liver  tissue.  In  general,  no  constant  relation  of  pentose 
to  origin,  malignancy,  or  degeneration  of  tumors  was  observed. 
The  most  significant  suggestion  of  this  and  other  work  by  the 
same  author  is  that  the  composition  of  a  metastatic  growth 
may  be  modified  by  its  environment,  so  that  it  may  differ  from 
the  primary  growth  more  than  from  the  normal  tissue  in  which 
it  has  taken  root. 

(3)  Inorganic  Constituents.  —  These  have  been  studied 
under  exceptionally  favorable  conditions,  in  that  the  age  of  the 
tumor  could  be  accurately  estimated,  in  the  inoculable  carcin- 
oma of  mice  (Jensen),  by  Clowes  and  Frisbie.4  They  found 
that  rapidly  growing  tumors  contain  a  high  percentage  of  potas- 
sium and  little  or  no  calcium,  whereas  in  old,  slowly  growing, 


Rend.  Soc.  Biol.,  1900  (52),  324. 
2Berl.  Win.  Woch.,  1904  (41),  1081  ;  1905  (42),  118. 
3Amer.  Jour.  Physiol.,  1905  (14),  231. 
*Amer.  Jour.  Physiol.,  1905  (14),  173. 


416  THE  CHEMISTRY  OF  TUMORS 

relatively  necrobiotic  tumors  the  relation  is  reversed,  the  potas- 
sium decreasing  greatly  while  the  calcium  increases.  Magne- 
sium is  present  only  in  traces,  while  the  proportion  of  sodium 
fluctuates  much  less,  but  is  usually  greater  than  either  the 
potassium  or  calcium,  although  in  very  old  tumors  the  latter 
may  become  excessive.  The  most  rapid  growth,  however, 
seems  to  occur  in  tumors  in  which  both  calcium  and  potassium 

T7-  ey  o 

are  present  in  the  ratio  of  ~-  =  -  or  -. 

Beebe l  analyzed  a  number  of  human  tumors  with  the  follow- 
ing results :  Phosphorus  was  found  in  proportion  to  the 
amount  of  nuclear  material,  varying  from  0.139  per  cent, 
(uterine  fibroid)  to  1.06  per  cent,  (sarcoma).  Iron  varied  from 
0.013  per  cent,  to  0.064  per  cent.,  probably  depending  on  the 
amount  of  blood  and  nucleoproteids.  Calcium  is  most  abun- 
dant in  old  degenerated  tumors,  and  potassium  in  rapidly  grow- 
ing tumors.  These  results,  supported  by  Clowes  and  Frisbie's 
findings,  indicate  the  importance  of  potassium  for  cell  growth. 

Schwalbe 2  found  that  cancer-cells  contain  iron  in  a  condition 
demonstrable  by  the  Berlin-blue  reaction,  and  occurring  inde- 
pendent of  hemorrhages.  Tracy3  found  that  tumors  reacted 
microscopically  for  iron,  either  free  or  in  the  form  of  an 
albuminate,  only  in  areas  where  hemorrhage  had  occurred. 
Nuclear  or  organic  iron  could  be  detected  in  the  nuclei,  occur- 
ring in  a  network  arrangement.  In  other  words,  iron  occurs 
in  tumors,  both  quantitatively  and  qualitatively,  exactly  as  in 
normal  cells  of  the  same  type.  The  same  writer 4  found  in 
tumors,  by  microchemical  reactions,  that  phosphorus  in  the 
form  of  nucleoproteids  likewise  shows  no  essential  differences 
from  its  distribution  in  normal  tissues. 

In  this  connection  may  be  mentioned  the  observations  of 
Hemmeter,5  who  found  that  the  cells  of  carcinoma  of  the 
mammary  gland  will  shrink  when  placed  in  physiological  salt 
solution  or  in  the  serum  of  the  patient,  whereas  normal  cells 
swell  when  placed  in  cancer-juice.  This  suggests  that  the 
osmotic  pressure,  and,  by  inference,  the  amount  of  inorganic 
constituents,  is  lower  than  in  normal  tissues. 

(4)  Bnsymes. — The  rapid  and  extensive  autolysis  that 
occurs  in  tumors,  as  shown  both  morphologically  and  by  the 
presence  of  the  products  of  proteid  splitting  in  them,  indicates 

1  Amer.  Jour.  Physiol.,  1904  (12),  167. 

2  Cent.  f.  Path.,  1901  (12),  874. 

3  Jour.  Med.  Kesearch,  1905  (14),  1. 

4  Martha  Tracy,  Jour.  Med.  Kesearch,  1906  (14),  447. 
6  Amer.  Jour.  Med.  Sci.,  1903  (125),  680. 


INTERNAL  SECRETION  417 

that  tumor  cells  resemble  all  other  cells  in  possessing  intra- 
cellular  proteolytic  enzymes.  We  have  no  evidence  that  these 
enzymes  are  different,  either  qualitatively  or  quantitatively, 
from  those  of  corresponding  normal  tissues.  They  are  dis- 
cussed more  fully  under  the  subject  of  autolysis  (Chap.  iii). 
The  influence  of  radium  rays  in  hastening  autolysis  of  cancers 
is  even  greater  than  that  of  x-rays  (Neuberg  *). 

Other  enzymes  are  also  present  in  tumor  cells.  Buxton 2 
examined  a  large  number  of  tumors  for  their  enzymes  by  the 
plate  (auxanographic)  method,  and  found  considerable  varia- 
tions in  different  growths.  All  contained  amylase  (splitting 
starch)  and  lipase  (splitting  butyrin).  Most,  but  not  all, 
tumors  coagulated  milk  and  liquefied  casein,  and  also  liquefied 
gelatin  (rennin,  proteases).  Peroxidase  was  nearly  always, 
and  catalase  always,  present.  Digestion  of  fibrin,  coagulated 
serum,  and  coagulated  egg-albumen  could  not  be  observed. 
Practically  all  tumors  split  glycogen.  Tyrosinase  could  not  be 
demonstrated.  The  fact  that  early  embryonic  tissues  were 
found  poor  in  enzymes3  speaks  against  the  common  assumption 
that  tumors  represent  strictly  an  embryonic  formation. 

MacFadyen  and  Harden4  studied  the  juices  obtained  by 
grinding  up  tumor  cells  made  brittle  by  liquid  air,  and  found 
by  direct  methods  (chiefly  in  breast  cancers)  invertase,  maltase, 
amylase,  proteases  acting  in  both  acid  and  alkaline  solutions, 
catalase,  oxidase,  with  perhaps  traces  of  lipase  and  peroxidase, 
but  no  lactase. 

Tumors  arising  from  the  gastric  mucosa,  according  to  War- 
ing,5 contain  both  pepsin  and  rennin ;  those  from  the  pancreas, 
both  primary  and  secondary  growths,  contain  trypsin,  steapsin, 
amylase,  and  rennin. 

(5)  Internal  Secretion. — If  tumors  are  derived  from  an 
organ  with  an  important  internal  secretion,  the  tumor  cells  in 
many  cases  produce  the  same  internal  secretion,  which  seems  to 
have  the  same  functional  properties  as  the  normally  produced 
secretion.  Thus  a  metastatic  growth  from  a  thyroid  tumor 
has  been  known  to  functionate  in  place  of  the  resected  gland ; 
Gierke6  found  in  about  20  grams  of  material  from  metastatic 
thyroid  tissue  in  the  vertebral  column  about  5  mg.  of  iodin, 
which  was  a  trifle  larger  proportion  than  was  present  in  the 

1  Arb.  a.  d.  Path.  Inst.  zu  Berlin,  1906,  p.  593. 

2  Jour.  Med.  Eesearch,  1903  (9),  356. 
8  Ibid.,  1905  (13),  543. 

4  Lancet,  1903  (ii),  224. 

5  Jour.  Anat.  and  Physiol.,  1894  (28),  142. 

6  Hofmeister's  Beitr.,  1902  (3),  286. 

27 


418  THE  CHEMISTRY  OF  TUMORS 

thyroid  itself.  Adrenal  cancers  do  not  usually  cause  Addison's 
disease,  because  they  functionate  in  place  of  the  destroyed  gland 
(Lubarsch).  But  in  the  peculiar  and  characteristic  production 
of  cachexia,  often  apparently  out  of  all  proportion  to  the 
amount  of  tumor  tissue,  there  would  seem  to  be  evidence  that 
a  peculiar  and  abnormal  product  of  metabolism  is  formed  by 
cancer-cells.  As  yet,  however,  it  has  been  impossible  to 
demonstrate  any  characteristic  toxic  substance  in  cancers.1 

Because  of  the  constant  disintegration  of  the  tumor  tissues, 
products  of  autolysis  are  formed,  and  undoubtedly  enter  the 
circulation  in  small  quantities ;  possibly  they  are  a  factor  in  the 
systemic  manifestations  of  malignant  growths,  but  it  is  highly 
doubtful  whether  they  are  sufficient,  either  in  toxicity  or  quan- 
tity, to  account  for  all  the  systemic  effects. 

Since  all  normal  tissue-cells  produce  substances  through 
their  metabolism  that  enter  the  circulation,  it  is  quite  certain 
that  tumor-cells  do  likewise,  and  it  is  highly  probable  that  the 
presence  of  abnormal  quantities  of  such  products,  even  if  they 
are  of  quite  normal  composition,  may  cause  disturbances  in  the 
body.  As  yet,  however,  no  such  substances,  either  normal  or 
abnormal,  have  been  isolated,  nor  has  their  presence  been 
demonstrated.  Numerous  isolated  observations  of  ptomai'ns  or 
similar  substances  in  the  urine  of  cancer  patients  may  be  found 
in  the  literature,2  but  their  importance  is  extremely  question- 
able. 

Hemolytic  Substances. — A  number  of  observers  have  de- 
scribed the  finding  of  hemolytic  substances  in  cancer  extracts. 
Bard3  observed  that  in  hemorrhagic  carcinomatous  exudates  in 
serous  cavities  the  blood  is  rapidly  hemolyzed,  which  is  not  the 
case  in  exudates  from  other  causes.  Kullmann 4  found  that 
extracts  of  carcinomas  contain  hemolytic  substances  acting 
energetically  both  in  the  body  and  in  vitro ;  these  are  soluble 
in  alcohol  and  in  water,  are  not  complex  in  composition,  are 
not  specific  for  human  corpuscles,  but  are  toxic  for  all  varieties 
of  corpuscles.  Micheli  and  Donati 5  likewise  found  hemolytic 
substances  in  8  of  15  tumors,  of  which  5  acted  on  all  varieties 
of  corpuscles,  and  3  acted  on  only  certain  varieties ;  they  regard 
the  hemolytic  substances  as  the  products  of  autolysis  in  the 
tumors.  It  is  well  known  that  among  the  products  of  autolysis 
of  normal  tissues  are  hemolytic  substances.  Whether  the  severe 

1  See  Blumenthal,  Festschr.  f.  Salkowski,  Berlin,  1904. 

2  See  Kullmann,  Zeit.  klin.  Med.,  1904  (53),  293. 

3  La  Semaine  Med.,  1901  (21),  201. 
*  Loc.  tit. 

5  Kiforma  Med.,  1903  (19),  1037. 


METABOLISM  IN  CANCER  419 

anemia  frequently  present  in  carcinoma  is  due,  either  largely  or 
in  part,  to  these  products  of  autolysis  is  unknown,  but  it  is  very 
probable  that  they  have  some  effect. 

(6)  Metabolism    in    Cancer.  —  Speaking    against  any 
specific  nature  in  the  cause  of  cancer  cachexia  are  numerous 
observations,  indicating  that  the  cachexia  is  in  no  way  different 
from   the  cachexia  of  other  conditions.     The  behavior  of  the 
nitrogen  metabolism  seems  to  be  quite  the  same  as  in  tubercu- 
losis and  other  wasting  diseases.     There  is  the   same  excessive 
elimination  of  aromatic  substances  (phenol,  indican)  and   oxy- 
acids  ('Lewin,1  Blumenthal  2  ),  which  Lewin  considers  to  arise 
from  the  abnormal  metabolism  of  proteids,  and  not  from  putre- 
factive decomposition  in  the  tumor  or  in  the  intestines.     There 
is  also  the  same  excessive  elimination  of  mineral  salts  observed 
in  pulmonary  tuberculosis,  and  termed  "  demineralization  "  by 
Robin.3 

Israel,  and  also  Engelmann,  have  reported  the  occurrence  of 
a  marked  increase  in  the  lowering  of  the  freezing-point  of  the 
blood  in  carcinoma  (as  low  as  —  0.60°  to  —  0.63°,  the  normal 
being  —  0.56°),  which  they  attributed  to  the  presence  of  exces- 
sive products  of  proteid  decomposition  in  the  blood.  Engel,4 
however,  found  no  such  increased  lowering  of  the  freezing- 
point  in  his  cases,  and  questions  the  significance  of  the  results 
of  Israel  and  Engelmann. 

(7)  Immunity  against  Cancer.  —  Numerous  attempts  to 
produce  specific  anti-bodies  for  malignant  cells  have  been  made 
by  injecting  into  animals  ground-up  tumor  tissue,  or  the  blood 
of  cancer  patients,  or  normal  tissues  of  the  same  origin  as  the 
cancer.5    The  results  have  generally  been  negative,  and  the  most 
favorable   reports   have  been  entirely   unconvincing.        Many 
difficulties,  as  yet  but  incompletely  surmounted  (see  Chap,  ix), 
lie  in  the  way  of  securing  specific  antiserum  for  particular  cells  ; 
the  difficulties  in  the  case  of  malignant  growths  is  even  greater, 
and  at  the  time  of  writing  the  possibilities  of  therapeutic  success 
by  this  method  are  not  promising. 

Kullmann6  found  that  the  serum  of  animals  immunized 
against  cancer  tissue  exhibits  strong  hemolytic  properties.  This 


med.  Woch.,  1905  (31),  218. 

2  Festschr.  f.  Salkowski,  Berlin,  1904. 

'Quoted  by  Lewin,  loc.  cit.  Clowes  et  al.  (5th  Ann.  Rep.,  N.  Y.  State 
Dept.  of  Health,  1903-4)  report  observing  a  slight  chloride  retention  in  cancer 
patients,  and  review  the  literature  of  metabolism  in  cancer. 

*  Berl.  klin.  Woch.,  1904  (41),  828. 

5  Literature  by  Engel,  Deut.  med.  Woch.,  1903  (29),  897. 

6  Loc.  cit. 


420  THE  CHEMISTRY  OF  TUMORS 

formation  of  hemolysins  in  immunization  against  tissues,  even 
when  comparatively  (or  completely)  free  from  blood,  has  fre- 
quently been  observed  when  normal  cells  have  been  injected,  and 
it  is  not  due  to  a  biological  modification  of  non-specific  hemo- 
lytic  substances  present  in  the  cancer,  as  Kullmann  suggests. 

B.  CHEMISTRY  OF  CERTAIN  SPECIFIC  TUMORS 

In  the  literature  are  to  be  found  a  few  studies  of  chemical 
features  of  some  forms  of  tumors,  which  may  be  briefly  dis- 
cussed to  advantage. 

(I)  BENIGN  TUMORS 

(a)  Fibromas. — The  few  specimens  studied  show  but  a  small 
amount  of  nucleoproteid,  as  might  be  expected  from  the  small 
amount  of  their  nuclear  material.  Because  of  the  tendency  of 
fibromas  to  undergo  retrogressive  changes,  the  amount  of  cal- 
cium is  likely  to  be  large.  No  studies  as  to  the  special  features 
of  their  collagen,  as  compared  with  normal  connective-tissue 
collagen,  seem  to  have  been  made.  Lubarsch l  found  no  gly co- 
gen  (microscopically)  in  any  of  66  fibromas  he  examined. 

A  uterine  fibroid  analyzed  by  Beebe2  contained  14.56  per 
cent,  of  nitrogen,  0.981  per  cent,  of  sulphur,  0.139  per  cent, 
of  phosphorus,  0.013  per  cent,  of  iron,  0.12  per  cent,  of  calcium 
oxide,  0.44  per  cent,  of  potassium,  and  1.115  per  cent,  of 
sodium.  The  proportions  of  nitrogen  and  sulphur  are  high  as 
compared  with  most  tumors ;  the  phosphorus,  iron,  and  potas- 
sium are  low,  corresponding  to  the  small  amount  of  nucleopro- 
teid and  the  slow  rate  of  growth.  If  degeneration  is  marked, 
the  amount  of  calcium  is  greatly  increased.  Krawkow 3  found 
a  trace  of  chondroitin-sulphuric  acid  in  a  uterine  fibroid. 
Lubarsch  found  glycogen  occasionally  in  richly  cellular  uterine 
leiomyomas,  and  in  the  vicinity  of  degenerating  areas ;  how- 
ever, 76  out  of  85  showed  no  glycogen.  Pfannenstiel 4  ana- 
lyzed the  alkaline  fluid  of  a  cystic  fibromyoma,  which  coagu- 
lated spontaneously ;  it  contained  sugar,  but  no  mucin  or 
pseudomucin.  The  cysts  were  dilated  lymph-spaces,  and  the 
fluid  corresponded  to  lymph  in  composition.  A  similar  result 
was  obtained  by  Oerum,5  who  found  in  the  fluid  serum-albumin, 
serum-globulin,  and  0.358  per  cent,  of  fibrin  ;  the  total  proteids 

1  Virchow's  Arch.,  1906  (183),  188. 
2Amer.  Jour.  Physiol.,  1904  (12),  167. 

3  Arch.  exp.  Path.  u.  Pharm.,  1898  (40),  195. 

4  Arch.  f.  Gyn.,  1890  (38),  468. 
5Maly's  Jahresber.,  1884  (14),  462. 


BENIGN  TUMORS 


421 


constituted  6.3056  per  cent.  Sollmann *  found  in  the  "  colloid  " 
of  a  cystic  degenerated  fibromyorna  both  pseudomucin  and  para- 
mucin  (see  "  Ovarian  Cysts  "),  which  differed  somewhat  from 
the  same  substances  found  in  ovarian  tumors. 

(6)  Chondromas,  like  normal  cartilage,  always  contain 
much  glycogen  (Lubarsch).  Morner2  found  chondroitin -sul- 
phuric acid  in  several  chondromas  that  he  examined,  although 
Schmiedeberg  had  failed  to  do  so. 

(c)  I/ipomas  have  been  studied  by  Schulz  3  and  by  Jaeckle.4 
The  former  found  in  a  retroperitoneal  lipoma  75.75  per  cent, 
of  fat,  2.25  per  cent,  of  connective  tissue,  and  22  per  cent,  of 
water.  Of  the  fat,  7.31  per  cent,  was  in  the  form  of  the  free 
fatty  acids  and  92.7  per  cent,  as  neutral  fats.  The  fatty  acids 
of  the  fat  consisted  of  65.57  per  cent,  oleic  acid ;  29.84  per 
cent,  stearic  acid ;  4.59  per  cent,  palmitic  acid.  Cholesterin 
was  only  qualitatively  demonstrable.  In  the  connective  tissue 
was  found  chondroitin-sulphuric  acid.  Lubarsch  found  glyco- 
gen in  lipomas  only  when  they  were  degenerated.  Jaeckle 
observed  the  formation  of  calcium  soaps  in  a  calcifying  lipoma, 
the  calcium  being  distributed  as  follows :  calcium  soaps,  29.5 
per  cent. ;  calcium  carbonate,  28.61  per  cent. ;  calcium  phos- 
phate, 41.89  per  cent.  The  fats  of  lipomas  he  found  practi- 
cally identical  with  those  of  the  subcutaneous  tissues,  except 
sometimes  for  a  deficiency  in  lecithin,  as  shown  by  the  follow- 
ing figures  : 

COMPOSITION  OF  FATS  IN — 


Subcutane- 
ous tissue. 

Lipoma 

Lipoma 

Lipoma 
III. 

Kefraction,  at  40°  .... 

50.6 

50.1 

50.9 

50.5 

Saponification  number    .    . 
Reichert-Meisser  number  . 

197.3 
0.25 

197.7 
0.33 

197.7 
0.35 

195.9 
0.35 

lodin  number  

63.7 

59.0 

64.0 

64.1 

Olein      

741 

686 

744 

745 

Oleic  acid      

709 

65.7 

71  2 

713 

Acid  number    

039 

031 

0.48 

067 

Free  acid  .        

0196 

0.155 

0.24 

0.34 

Palmitic  acid 

185 

249 

185 

Stearic  acid 

62 

5  1 

59 

Lecithin     .        ... 

0084 

0015 

Cholesterin    

0.32 

•    • 

0.34 

Edsall  found  the  composition  of  the  fat  in  the  fatty  tumors  of  adiposis  dolo- 
rosa  but  little  different  from  that  of  normal  fat.5 


2  Zeit.  physiol.  Chem.,  1895  (20),  357. 
4  Zeit.  physiol.  Chem.,  1902  (36),  53. 


1  Amer.  Gynecol.,  1903  (2),  232. 
3  En-tiger's  Arch.,  1893  (55),  231. 
5  Quoted  by  Dercum  and  McCarthy,  Amer.  Jour.  Med.  Sci.,  1902  (124),  994. 


422  THE  CHEMISTRY  OF  TUMORS 

(d)  Ovarian  cyst  contents  have  been  studied  more  than 
almost  any  other  tumor  products,  because  in  their  gelatinous  or 
slimy  substance  are  contained  numerous  interesting  forms  of. 
proteids,  many  of  which  are  combined  with  carbohydrates  and 
related  to  the  true  mucins.  These  substances  are  frequently 
referred  to  under  the  names  of  pseudomucin,  par  albumin,  metal- 
bumin,  and  ovarian  " colloid"  and  belong  to  the  class  of 
"  mucoids."  l  In  view  of  the  fact  that  the  fluids  in  the  Graafian 
follicles  of  the  ovary  do  not  contain  these  particular  forms  of 
proteid,  their  presence  in  cysts  derived  from  adventitious  struc- 
tures (Pfliiger's  epithelial  tubes)  suggests  a  specific  form  of 
metabolism  on  the  part  of  the  epithelium  of  these  structures. 

Serous  cysts,  formed  by  dilatation  of  Graafian  follicles,  usually 
are  small  in  size,  and  the  contents  resemble  those  of  the  normal 
follicles  (Oerum2),  consisting  of  a  serous  fluid  with  a  specific 
gravity  usually  from  1.005  to  1.014  (occasionally  1.020  or 
more),  and  containing  1.0-4.0  per  cent,  of  solids.  Occasion- 
ally in  these  cysts  the  contents  become  solidified  through 
absorption  of  the  water,  and  a  gelatinous  or  glue-like  "  colloid  " 
content  results.  Mucoids  are  never  present  (Pfannenstiel 3). 

Proliferating  cystomas  contain  the  peculiar  characteristic 
mucoid  proteids  mentioned  above.  Usually  the  contents  are 
fluid,  but  of  a  peculiar  slimy,  stringy  character,  due  to  the  mucoid 
substance,  and  often  opalescent  or  slightly  turbid.  The  specific 
gravity  is  generally  high — 1.015-1.030.  The  reaction  is  usually 
slightly  alkaline  to  litmus,  and  neutral  or  slightly  acid  to  phenol- 
phthalein.  If  hemorrhage  has  occurred  into  them,  the  fluid  is 
discolored,  and  may  contain  blood-pigments  in  crystalline  and 
amorphous  forms.  Small  cysts  often  show  a  condensation  of 
the  proteids  into  a  semisolid  "  colloid  "  material,  but  sometimes 
their  contents  resemble  those  of  a  serous  cyst.  Often  masses 
of  proteids  fall  out  of  solution,  forming  yellowish  flocculi  or 
large  deposits  half  filling  the  cysts.  As  with  all  stagnant  fluids 
of  this  type,  cholesterin  crystals  are  frequently  found.  The 
characteristic  proteids  are  members  of  the  class  of  pseudo- 
mucins,  which  are  constantly  present  (Oerum). 

Chemistry  of  the  Mucoids  of  Ovarian  Cysts.— Pseudomucin  has 
the  following  elementary  composition:  C,  49.75;  H,  6.98;  N,  10.28; 
S,  1.25  ;  O,  31.74  per  cent.  (Hammarsten).  In  common  with  the  true 
mucins  it  yields  a  sugar-like  reducing  body,  which  has  been  investigated 

1  Concerning  mucoids  see  Mann's  "  Chemistry  of  the  Proteids,"  1906,  pp. 
541-551. 

2  See  Maly's  Jahresbericht,  1884  (14),  459. 

3  Arch.  f.  Gynsek.,  1890  (38),  407  (literature). 


BENIGN  TUMORS  423 

by  numerous  chemists  (Miiller,  Panzer,  Zangerle,  Leathes,  Neuberg,  and 
Heyinann1).  Panzer  considers  that  this  reducing  substance  is  in  the 
form  of  a  sulphuric-acid  compound,  similar  to,  but  not  identical  with, 
chondroitin-sulphuric  acid.  Hammarsten,  however,  did  not  find  this 
substance  constantly  present.  Leathes  determined  for  the  carbohydrate 
group  the  composition  C12H23N010,  named  it  " paramucosin,"  and  con- 
siders it  a  reduced  chondrosin  (which  is  the  carbohydrate  group  of 
chondroitin-sulphuric  acid).  Neuberg  and  Heymann  established,  how- 
ever, that  the  reducing  body  must  come  from  chitosamin  (C6H13NO5), 
and  do  not  consider  paramucosin  a  constant  constituent  of  ovarian 
mucoids.  The  amount  of  reducing  substance  varies  greatly  in  the 
mucoids  found  in  different  cysts ;  in  some  the  mucoid  yields  but  about 
3  to  5  per  cent.,  in  others  as  much  as  30  or  35  per  cent.,  of  reducing 
substance. 

Pseudomucin  dissolves  readily  in  weak  alkalies,  and  differs  from  true 
mucin  in  that  it  is  not  precipitated  by  acetic  acid,  and  from  the  simple 
proteids  in  that  its  solutions  are  not  coagulated  by  boiling.  With  water 
a  slimy,  stringy  semi-solution  is  formed,  resembling  in  appearance  the 
material  found  in  ovarian  cysts.  Leathes  distinguishes  two  forms  of 
ovarian  mucoids  :  One,  paramucin,  occurs  as  a  firm,  jelly-like  substance, 
which  is  converted  by  peptic  digestion  into  the  easily  soluble  pseudo- 
mucin.  Ovarian  ' '  colloid ' '  probably  consists  of  a  thickened  pseudo- 
mucin,  often  mixed  with  other  proteids.  Pfannenstiel2  considers  the 
"colloid"  material  as  representing  a  modified  pseudomucin,  strongly 
alkaline  and  relatively  insoluble,  which  he  calls  "pseudo-mucin  /?." 
He  also  describes  a  very  soluble  mucoid  found  only  in  certain  ovarian 
cysts,  naming  it  " pseudo-mucin  y." 

The  reasons  why  these  variations  in  the  pseudomucins  exist 
is  not  understood  ;  they  cannot  be  explained  as  due  to  variations 
in  the  cell  type  in  the  cyst  wall,  although  pseudomucin  is  prob- 
ably the  result  of  true  secretion.  The  smallest  cavities  of 
ovarian  cystadenomas  contain  nearly  pure  pseudomucin,  which 
presents  a  clear,  glassy  structure ;  the  larger  the  cysts  become, 
and  the  more  turbid  and  thinner  the  fluid  is,  the  more  simple 
are  the  proteids  it  contains.  True  mucin  is  never  present  in 
ovarian  cysts.  Pseudomucin  occurs  only  in  the  glandular 
proliferating  cystomas  and  the  papillary  proliferating  cyst- 
adenomas,  in  the  former  appearing  constantly  and  abundantly, 
in  the  latter  not  constantly  and  never  abundantly  (Pfannenstiel). 
Paralbumin  (Scherer)  is  a  mixture  of  pseudomucin  with  variable 
amounts  of  simple  proteids.  Metalbumin  (Scherer)  is  the  same 
body  that  is  called  pseudomucin  by  Hammarsten.  Paramucin 
(Mitjukoff  )3  is  a  mucoid  differing  from  mucin  and  pseudomucin 
in  reducing  Fehling's  solution  directly,  without  having  the 
carbohydrate  group  first  split  off  by  boiling  with  an  acid. 

1  Hofmeister's  Beitr.,  1902  (2),  201  (literature). 

2  Loc.  cit. 

3  Arch.  f.  Gynsek.,  1895  (49),  278. 


424  THE  CHEMISTRY  OF  TUMORS 

Substances  similar  to  pseudomucin  have  been  occasionally 
found  in  cancerous  ascitic  fluid  and  in  cystic  fibromyomas  (Soil- 
man  n)  ;  and  they  are  abundant  as  constituents  of  the  contents 
of  the  peritoneum  in  the  condition  known  as  "  pseudomyxoma 
peritonei,"  l  when  the  material  is  in  reality  the  product  of  cells 
implanted  on  the  peritoneal  surface  through  the  bursting  of 
an  ovarian  cyst  (or  a  cyst  of  the  vermiform  appendix  (Frankel2 )). 
The  physically  similar  substance  found  in  pathological  synovial 
membranes  by  Hammarsten  differs  in  yielding  no  reducing 
substance.  Parovarian  cysts  arising  from  the  Wolffian  body 
present  an  entirely  different  content,  which  is  a  clear,  watery 
fluid,  with  specific  gravity  usually  under  1.010;  the  solids 
amount  to  but  1  or  2  per  cent.,  and  consist  chiefly  of  salts 
(the  ash  being  often  over  80  per  cent.),  mostly  sulphates  and 
chlorides.  They  are  usually  (or  always)  free  from  pseudomucin, 
mucin,  or  other  sugar-containing  substances,  and  other  proteids 
occur  only  in  small  amounts,  unless  the  cyst  is  inflamed. 
Apparently  mucoids  do  not  form  in  cysts  lined  by  ciliated 
epithelium  (Pfannenstiel). 

Intraligamentary  papillary  cysts  contain  a  yellow,  yellow- 
ish-green, or  brownish-green  liquid,  which  contains  little  or  no 
pseudomucin;  the  specific  gravity  is  usually  high  (1.032— 1.036) 
and  the  fluid  contains  9  to  10  per  cent,  of  solids.  The  principal 
constituents  are  the  simple  proteids  of  blood-serum  (Hammar- 
sten). 

According  to  the  same  author,  the  rare  tubo-ovarian  cysts 
contain  a  watery  serous  fluid  with  no  pseudomucin. 

(e)  Dermoid  cysts  of  the  ovary  contain,  as  their  chief 
and  most  characteristic  constituent,  a  yellow  fat,  which  melts 
at  34°-39°  and  solidifies  at  20°-25°.  Ludwig  and  Zeynek  3 
have  examined  over  sixty  such  tumors,  and  found  that  the 
fatty  material  constantly  contains  two  chief  constituents  :  one, 
crystallizing  out  readily,  seems  to  be  cetyl  alcohol, 

(CH3-(CH2)U-CH2OH); 

the  other,  remaining  as  an  oily  fluid,  seems  to  be  closely  re- 
lated to  cholesterin,  although  not  consisting  of  one  substance 
alone.  Small  quantities  of  arachidic  acid  (C20H40O2),  as  well 
as  stearicj  palmitic,  and  myristic  acid  (C14H28O2),  existing  as 
glycerides,  are  also  present.  These  substances  are  secreted 

1  Literature  by  Peters,  Monatschr.  f.  Geb.  u.  Gyn.,  1899  (10),  749 ;  Weber, 
St.  Petersb.  med.  Woch.,  1901  (26),  331. 

2  Munch,  med.  Woch.,  1901  (48),  965. 

3  Zeit.  physiol.  Chem.,  1897  (23),  40. 


MALIGNANT  TUMORS  425 

by  the  glands  of  the  cutaneous  structures  of  the  cyst,  and 
resemble  in  composition  sebaceous  material,  which  is  charac- 
terized by  containing  a  large  proportion  of  cholesterin  partly 
combined  with  fatty  acids. 

(/)  "  Butter  "  Cysts. — In  the  mammary  gland  retention 
cysts  form,  filled  with  products  of  alteration  of  the  milk, 
including  butyric  acid  and  lactose  (Klotz1),  and  these  are 
called  "butter  cysts"  or  milk  cysts.  Analysis  of  the  contents 
of  such  a  cyst  by  Smita 2  gave  the  following  results,  as  compared 
with  human  milk : 

Cyst  contents.    Human  milk. 

Fat 72.97  3.90 

Casein      4.37  0.63 

Albumin      1.91  1.31 

Milk-sugar 0.88  6.04 

Ash 0.36  0.49 

Water 20.81  87.09 

Fats  consisted  of—  Cyst.  Cows,  milk- 

Stearin  and  palmitin -    .    .  37.0  50.0 

Olein 53.0  42.2 

Butyrin 9.0  7.8 

Occurring  independent  of  lactation  usually,  but  not  always, 
are  the  "  soap  cysts,"  which  contain  chiefly  calcium  and  mag- 
nesium soaps,  but  also  neutral  fats,  free  fatty  acids,  and  traces 
of  cholesterin  (Freund3). 

(2)  MALIGNANT  TUMORS 

The  chief  general  features  of  the  composition  of  these  growths 
have  been  considered  in  the  discussion  of  the  chemistry  of  tumors 
in  general  (pages  412-420).  A  malignant  tumor  diifers  from  a 
similar  benign  tumor  chiefly  in  having  usually  a  larger  proportion 
of  the  primary  cell  constituents,  and  a  smaller  proportion  of  the 
secondary  constituents  and  intercellular  substances,  since  these  are 
largely  the  product  of  the  functional  activity  of  the  cells,  which, 
in  malignant  tumors,  do  not  often  develop  sufficiently  to  func- 
tionate extensively.  Hence  malignant  tumors  usually  show  a 
rather  high  proportion  of  the  characteristic  constituents  of  nucleo- 
proteids  ;  i.  e.,  phosphorus  and  iron.  If  rapidly  growing,  they 
contain  much  potassium ;  if  undergoing  much  retrogression,  little 
potassium  and  a  larger  amount  of  calcium  (Beebe,  Clowes  and 
Frisbie).  On  account  of  the  extensive  disintegration,  the 
products  of  autolysis  are  usually  much  more  abundant  than  in 

1  Arch.  klin.  Chir.,  1880  (25),  49. 

2  Wien.  klin.  Woch.,  1890  (3),  551. 

3  Virchow's  Arch.,  1899  (156),  151. 


426  THE  CHEMISTRY  OF  TUMORS 

benign  tumors.  The  composition  varies  greatly  with  the  origin, 
although  to  a  less  extent  than  with  the  benign  tumors.  As 
Bang  and  Beebe  have  shown,  the  tumors  arising  from  lymphatic 
tissues  show  the  chemical  characteristics  of  these  structures,  and 
contain  histon  nucleinate.  Tumors  from  squamous  epithelium 
develop  keratin  in  direct  proportion  to  the  amount  of  maturity 
the  cells  reach.  Even  the  most  complex  and  specific  products 
of  metabolic  activity  may  be  developed  by  malignant  tumors 
(e.  g.j  thyroiodin,  adrenalin,  bile),  and  in  a  form  and  condition 
capable  of  performing  function.  As  Buxton  has  shown,  malig- 
nant tumors  produce  a  great  variety  of  intracellular  enzymes. 
The  idea  that  glycogen  is  present  in  tumors  in  proportion  to 
their  malignancy  has  been  disproved  by  Lubarsch,  Gierke,  and 
others  ;  among  the  malignant  tumors  glycogen  is  found  particu- 
larly in  chorioepitheliomas,  hypernephromas,  and  squamous  cell 
carcinomas.  Of  particular  importance  is  the  observation  of 
Beebe,  that  the  composition  of  metastatic  growths  is  modified 
by  the  organ  in  which  they  are  growing,  so  that  they  tend  to 
resemble  the  organ  serving  as  their  host. 

As  to  the  special  varieties  of  malignant  growths,  there  is  little 
as  yet  determined  concerning  their  chemistry  beyond  what  has 
been  stated  above.  Their  variations  in  composition  are  largely 
the  direct  result  either  of  their  resemblance  to  some  normal 
tissue  or  of  degenerative  changes  that  they  have  undergone. 

"  Colloid  "  carcinoma  may  be  mentioned  specially,  in  view 
of  the  confusion  caused  by  the  lax  use  of  the  term  "  colloid  " 
(q.  v.,  p.  354).  The  fluid  contents  of  colloid  cancers  of  the 
gastro-intestinal  tract  are  usually  chiefly  epithelial  mucus,  con- 
taining mucin  mixed  with  a  greater  or  less  quantity  of  proteids 
from  degenerated  cells  and  serous  effusion.  This  mucin  is  acid 
in  reaction,  is  precipitated  by  acetic  acid,  and  has  an  affinity  for 
basic  dyes.  The  colloid  cancers  of  the  mammary  gland,  in  which 
the  "  colloid  degeneration  "  involves  the  stroma,  probably  contain 
a  connective-tissue  mucin,  analogous  to  that  of  the  umbilical  cord, 
as  also  do  the  myxosarcomas,  if  we  may  judge  by  their  origin 
and  staining  reactions,  but  no  exact  chemical  study  of  these 
substances  can  be  found.  Colloid  cancers  of  the  ovary,  arising 
usually  from  the  same  structures  as  the  ovarian  cysts,  contain 
pseudomucin  or  allied  bodies  (see  "  Ovarian  Cysts  ").  Colloid 
tumors  of  thyroid  tissue  contain  the  typical  colloid  of  normal 
thyroid  tissue,  even  when  metastatic  in  other  organs  ;  in  the 
tumor  colloid  is  a  relatively  normal  proportion  of  iodin 
(Gierke1). 

1  Hofmeister's  Beitr.,  1902  (3),  286. 


MULTIPLE  MYELOMAS  AND  "ALBUMOSUItIA"       427 

Hypernephromas  possess  several  interesting  chemical 
features.  For  example,  at  a  time  when  the  origin  of  these 
tumors  was  in  dispute,  Gatti l  brought  forward  the  fact  that  such 
a  tumor  analyzed  by  him  contained  3.4735  per  cent,  of  lecithin, 
which  agreed  very  well  with  the  amount  of  lecithin  in  normal 
adrenals.  Beebe 2  found  in  the  watery  extract  of  a  hyper- 
nephroma  the  following  substances  :  tryptophan,  proteoses,  gly co- 
gen,  leucin,  and  tyrosin,  indicating  the  occurrence  of  autolysis. 
About  29  per  cent,  of  fat  was  present,  which  was  all  extractable 
without  pepsin  digestion,  and  the  fat  contained  about  18  per 
cent,  of  its  weight  as  cholesterin.  Lecithin  was  also  present, 
but  not  quantitatively  determined.  Croftan 3  states  that  hyper- 
nephroma  tissue  resembles  adrenal  tissue  in  causing  glycosuria 
when  extracts  are  injected  subcutaneously  into  rabbits,  in  split- 
ting starch  into  sugar,  and  in  decolorizing  a  blue  iodin-starch 
solution.  The  last  of  these  reactions  is  given  by  so  many  other 
tissues,  however,  that  its  differential  value  is  doubtful. 

Melanotic  tumors  produce  melanin,  which  seems  not  to 
differ  at  all  from  the  melanin  found  in  normal  pigmented 
structures  (see  Chap.  xvi).  Helman 4  found  as  high  as  7.3  per 
cent,  by  weight  of  melanin  in  melanosarcomas. 

MULTIPLE  MYELOMAS  AND  MYELOPATHIC  "  ALBUMOSURIA  " 

Multiple  myelomas  are  of  particular  chemical  interest,  because 
of  the  appearance  in  the  urine  of  such  cases  of  the  peculiar  pro- 
teid  first  described  as  an  albumose  by  Bence-Jones,5  and  now, 
because  of  lack  of  grounds  for  its  definite  classification,  gener- 
ally known  as  the  "Bence-Jones  body  "  or  "Bence-Jones  proteid" 
This  variety  of  tumor  differs  from  the  standard  types  of  malig- 
nant tumors  in  that  it  involves  the  marrow  of  many  bones 
simultaneously,  in  a  very  diffuse  manner,  without  usually  giving 
evidence  of  a  true  metastasis.  In  many  respects  it  resembles  the 
leukemias,  pseudoleukemia,  and  chloroma,  and  it  is  extremely 
uncertain  as  to  where  in  the  classification  of  tumors  and  of  the 
diseases  of  the  blood-forming  organs  this  disease  should  be 
placed.  Histologically,  the  tumors  show  evidence  of  being 
derived  from  the  specific  cells  of  the  marrow,  either  from  the 

1  VirchoVs  Arch.,  1897  (150),  417. 

2  Amer.  Jour.  Physiol.,  1904  (11),  139. 
3Virchow's  Arch.,  1902  (169),  332. 

4  Arch,  internat.  Pharmacodyn.,  1903  (12),  271. 

5  References  not  generally  cited,  as  there  exist  several  complete  re'sume's  of 
the  literature ;  see  Simon,  Amer.  Jour.  Med.  Sci.,  1902  (123),  939 ;  Weber  et  a/., 
ibid.,  1903(126),  644;  Moffatt,  Lancet,  1905  (i),  207. 


428  THE  CHEMISTRY  OF  TUMORS 

plasma  cells  (Wright)  or  from  the  neutrophile  myelocytes  or 
their  predecessors  (Muir). 

Properties  of  the  "  Bence-Jones  Proteid." — Not  to  go 
into  details,  which  are  given  in  the  literature  cited,  the  impor- 
tant facts  concerning  the  "Bence-Jones proteid"  and  its  appear- 
ance in  the  urine  ("  myelopathic  albumosuria,"  Bradshaw),  are  as 
follows  : 

It  is  a  proteid,  the  exact  nature  of  which  has  not  been  deter- 
mined ;  at  first  considered  an  albumose  because  of  its  peculiar 
reactions  to  heat,  its  nature  has  since  been  contested,  but  the 
weight  of  evidence  seems  to  be  in  favor  of  the  contention  of 
Simon  that  it  is  most  closely  related  to  the  water-soluble  globu- 
lin of  'the  blood.  Its  most  characteristic  properties  are  the  fol- 
lowing : 

The  coagulation  temperature  is  low,  varying  from  49°-60°  in  various 
cases,  and  being  considerably  modified  by  the  amount  of  salts  and  urea 
present  in  the  solution. 

In  many  cases  the  coagulum  is  redissolved  on  heating,  and  reappears 
on  cooling,  but  this  characteristic  feature  is  not  always  present,  and 
often  disappears  in  cases  where  at  first  it  is  present. 

A  precipitate  is  formed  by  strong  (25  per  cent. )  nitric  acid,  which  dis- 
appears on  heating  and  reappears  on  cooling.  Strong  hydrochloric  acid 
causes  a  dense  precipitate,  which  is  quite  typical  (Bradshaw). 

No  precipitate  is  produced  by  acetic  acid,  even  in  excess,  and  the 
addition  of  acetic  acid  to  a  hot  coagulated  specimen  causes  prompt  solu- 
tion of  the  coagulum. 

Unlike  albumoses,  this  substance  does  not  dialyze  ;  the  salt-free  solu- 
tion left  in  the  dialyzing  bag  does  not  precipitate. 

A  purplish-violet  color  is  usually  given  with  the  biuret  reaction,  but 
it  may  be  more  reddish  in  color,  especially  if  little  copper  is  present. 

Sulphur  is  readily  split  off  by  alkalies,  reacting  with  lead  acetate  to 
produce  lead  sulphide  (Boston). 

After  standing  in  alcohol,  by  which  the  body  is  precipitated,  it  loses 
its  solubility  (differing  in  this  respect  from  albumose). 

As  to  the  exact  nature  of  the  body,  little  can  be  said  at 
the  present  time.  Since  protoproteoses,  deuteroproteoses,  and 
peptone  are  split  off  on  digestion  with  pepsin,  the  molecule  is 
evidently  larger  than  that  of  any  of  the  albumoses.  The  well- 
purified  substance  seems  to  be  free  from  phosphorus,  and  hence 
contains  no  nucleins  ;  but  it  contains  considerable  sulphur  (gen- 
erally between  1  and  2  per  cent.),  which  is  readily  split  off. 
Like  casein,  it  contains  no  hetero-group  (lack  of  heteroproteoses 
on  digestion),  but  differs  in  containing  a  carbohydrate  group  (in 
small  amount)  and  in  the  absence  of  phosphorus.  On  hydrol- 
ysis Magnus-Levy l  obtained  glutaminic  acid,  tyrosin,  and 
1  Zeit.  physiol.  Chem.,  1900  (30),  200. 


MULTIPLE  MYELOMAS  AND  "ALBUMOSURIA"       429 

leucin,  but  no  glycocoll.  He  found  the  nitrogen  distributed  as 
follows:  amid-nitrogen,  9.9  per  cent.;  humin-nitrogen,  9.8  per 
cent.  ;  diamino-nitrogen,  6.4  per  cent. — which  last  was  com- 
posed of:  histidin,  0.9  per  cent. ;  arginin,  2.4  percent. ;  lysin, 
3.0  per  cent.  Attempts  to  prove  the  identity  of  the  body  by 
the  precipitin  reaction  have  failed.1 

Occurrence  of  "  Myelopathic  Albumosuria." — At 
the  present  time  (1906)  there  are  between  forty  and  fifty  authen- 
ticated cases  of  "  myelopathic  albumosuria"  in  the  literature, 
but  the  number  is  rapidly  increasing  as  the  general  appreciation 
of  its  characteristics  is  widening.  Not  all  cases  of  multiple 
myeloma  show  the  presence  of  Bence-Jones  proteid  in  the  urine 
however.2  It  is  still  uncertain  as  to  whether  this  substance  is  pro- 
duced specifically  in  multiple  myeloma  or  is  present  occasion- 
ally in  other  conditions.  Multiple  bone  involvement  by  other 
tumors  does  not  cause  "  albumosuria."  3  There  is  no  evidence  that 
it  occurs  in  the  normal  body,  even  in  the  bone-marrow,  or  that 
it  is  produced  as  a  step  in  the  splitting  of  any  form  of  proteids. 
A  few  cases  of  supposed  osteomalacia  have  been  reported,  with 
the  Bence-Jones  body  in  the  urine,  but  on  more  careful  inves- 
tigation these  seem  to  have  been  unrecognized  myelomas  (e.  g.y 
the  cases  of  Bence-Jones  and  of  Jochmann  and  Schumm). 
Similarly  the  case  reported  by  Askanazy  as  leukemia  with 
Bence-Jones  proteid  in  the  urine,  on  reexamination  was  found 
to  be  multiple  myeloma.  Coriat 4  describes  a  substance  found 
in  a  pleuritic  fluid  which  gave  the  reactions  of  the  Bence-Jones 
body,  and  he  believes  that  it  may  have  been  formed  from  serum- 
globulin  through  the  digestive  action  of  the  leucocytes  or  bac- 
teria. Zuelzer  reports  finding  the  same  body  in  the  urine  of  a 
dog  poisoned  with  pyridin.5 

Origin  of  the  Proteid. — As  to  the  place  of  formation 
of  this  peculiar  proteid,  there  is  much  diversity  of  opinion. 
Magnus-Levy  advanced  against  the  idea  that  it  is  formed  by 
the  tumor  cells  the  following  arguments  :  In  the  urine  of 
myeloma  patients  are  excreted  great  quantities  of  the  proteid, — 
as  much  as  30  to  70  grams  per  day, — whereas  the  total  amount 
ef  proteid  in  all  the  tumor  tissue  in  the  body  seldom  exceeds, 

1  Rostoski,  Verb,  der  Phys.  Med.  Gesell.,  Wurzburg,  1902  (35),  30  ;  Munch, 
med.  Woch.,  1902(49),  740. 

2  See  Collins,  Med.  Record,  1905  (67)',  641. 

3  A  case  of   this  kind  has,  however,  recently  been   described   by  Oerum 
(Ugeskrift  f.  Lager,  1904,  No.  24),  in  which  the  bone  tumors  were  multiple 
metastases  of  a  gastric  carcinoma. 

*Amer.  Jour.  Med.  Sci.,  1903  (126),  631. 

5  Wohlgemuth  (Arb.  a.  d.  Path.  Inst.  zu  Berlin,  Festschrift,  1906,  p.  627) 
states  that  normal  human  bone  marrow  may  contain  true  albumoses. 


430  THE  CHEMISTRY  OF  TUMORS 

or,  indeed,  equals  this  quantity.  It  seems  improbable  that  so 
little  tumor  tissue  can  form  so  much  urinary  proteid,  and 
Magnus-Levy  suggests  that  it  must  come  from  the  food  pro- 
teids  as  a  result  of  altered  proteid  metabolism.  Against  this 
view,  however,  are  the  following  facts  :  (1)  The  Bence-Jones 
body  has  been  found  (but  not  constantly)  in  the  myeloma 
tissue,  but  not  in  other  organs  or  tissues  ;  (2)  the  quantity 
in  the  urine  is  not  dependent  upon  diet ; l  (3)  it  is  associated 
only  with  this  form  of  tumor.  Simon  considers  it  probable 
that  the  proteid  is  formed  from  serum-globulin,  perhaps  by 
an  enzymatic  action  of  the  tumor  cells,  and  once  formed,  it  is 
rapidly  eliminated  by  the  kidneys,  as  are  all  foreign  proteids. 

1  See  Allard  and  Weber,  Deut.  med.  Woch.,  1906  (32),  1251.  Voit  and 
Salyendi  (Munch,  med.  Woch.,  1904  (51),  1281),  however,  report  a  case  in 
which  diet  modified  the  elimination  of  the  "  albumose." 


CHAPTER    XVIII 

PATHOLOGICAL  CONDITIONS  DUE  TO,  OR  ASSO- 
CIATED WITH,  ABNORMALITIES  IN  METAB- 
OLISM, INCLUDING  AUTOINTOXICATION 

DUKING  the  course  of  metabolism  innumerable  organic  com- 
pounds are  formed,  some  of  which  are  of  a  more  or  less  poison- 
ous nature.  As  long  as  the  body  is  in  a  normal  condition,  these 
injurious  substances  are  kept  from  accumulating  in  sufficient 
quantities  to  do  harm  ;  this  is  accomplished  in  one  of  the  fol- 
lowing ways  :  (1)  Elimination  from  the  body  in  the  urine,  feces, 
etc. ;  (2)  combination  with  other  substances  into  harmless,  or 
relatively  harmless,  compounds ;  (3)  chemical  alteration  into 
compounds  that  are  non-toxic  or  relatively  innocuous.  There- 
fore a  harmful  accumulation  of  metabolic  products  may  be  the 
result  of  any  one  of  the  following  conditions  : 

(1)  Failure  of  elimination  because  of  abnormal  conditions  in 
the  eliminating  organs  ;  e.  g.,  uremia. 

(2)  Failure  of  neutralization  by  chemical  combination,  pre- 
sumably due  to  abnormalities  in  the  organs  or  tissues  through 
whose  activities  the  neutralization  is  normally  accomplished ; 
e.  g.j  diseases  of  the  liver. 

(3)  Failure  in  the  chemical  transformation  of  the  metabolic 
products;  this   may   result   either   from   abnormalities  in   the 
functionating  tissues,  or  through  a  checking  of  the  normal  steps 
of  metabolism  by  the  failure  of  elimination  of  the  end-products. 

(4)  Excessive  formation  of  certain  normal  products  of  metab- 
olism ;  e.  g.y  hyperactivity  of  the  thyroid. 

(5)  Production  of  abnormal  toxic  chemical  substances  ;  e.  g., 
the  intoxication  following  superficial  burns. 

Numerous  classifications  of  autointoxication  have  been  pro- 
posed by  various  authors,  some  excluding  from  the  causes  of 
autointoxication  all  but  the  products  of  metabolism  within 
the  blood  and  tissues  of  the  body,  as  has  been  done  in  the 
preceding  consideration  ;  many  including  intoxications  caused 
by  the  products  of  gastro-intestinal  fermentation  and  putre- 
faction ;  and  still  others  (v.  Jaksch)  including  even  the  intoxi- 
cations produced  by  bacterial  invasion  of  the  body.1  It  is 
1  See  resume'  by  Weintraud,  Ergeb.  der  Path.,  1897  (4),  1. 

431 


432  METABOLIC  ABNORMALITIES,  AUTOINTOXICATION 

extremely  difficult  to  draw  the  line  as  to  just  what  should 
be  included  under  the  term  autointoxication,  and  particularly 
difficult  to  decide  the  proper  placing  of  the  intoxication  result- 
ing from  fecal  retention  and  from  processes  of  decomposi- 
tion in  the  alimentary  canal.  For  example,  the  poisoning 
following  the  eating  of  partially  decomposed  canned  food 
could  not  be  looked  upon  as  an  autointoxication,  and  yet 
there  is  no  fundamental  difference  whether  the  decomposition 
occurs,  as  in  this  case,  before  the  food  enters  the  body,  or 
whether  it  occurs  in  the  intestinal  tract  because  of  abnormal 
bacteriological  or  anatomical  conditions.  On  the  other  hand, 
since  many  of  the  obnoxious  products  of  metabolism  are  elimi- 
nated through  the  bowels,  failure  of  elimination  through  this 
channel  may  lead  to  a  true  autointoxication  as  much  as  may 
deficient  renal  elimination.  On  the  whole,  it  seems  best  to  restrict 
the  term  autointoxication,  as  far  as  possible,  to  the  disturbances 
produced  by  products  of  metabolism  that  have  been  formed  within 
the  tissues  of  the  body  (intermediary  metabolism},  considering  as 
a  distinct  but  related  subject  gastro-intestinal  autointoxication. 

In  the  discussion  of  autointoxication  from  the  standpoint  of 
chemical  pathology,  we  are  interested  particularly  in  the  chem- 
ical nature  of  the  substances  that  cause  the  intoxication,  and  in 
the  chemical  processes  by  which  their  action  is  kept  at  a  min- 
imum, rather  than  in  the  clinical  features  or  anatomical  results 
that  may  be  produced.  Unfortunately,  in  but  a  few  instances 
have  the  exact  chemical  substances  causing  these  intoxications 
been  accurately  determined,  probably  because  in  most  cases  not 
one  but  a  number  of  poisonous  substances  are  present ;  and, 
furthermore,  we  do  not  always  know  exactly  when  a  certain 
disease  is  to  be  ascribed  to  autointoxication,  nor  can  we  always 
determine  that  the  cause  of  a  certain  intoxication  lies  in  an 
abnormality  in  metabolism  and  not  in  an  infection  of  hidden 
nature.  It  is,  therefore,  quite  impossible,  with  the  uncertain 
information  available  at  this  time,  to  consider  autointoxication 
in  a  systematic  way,  and  we  must  limit  ourselves  to  a  considera- 
tion of  certain  pathological  conditions  in  which  there  appears 
to  be  an  element  of  abnormal  metabolism  with  resulting  intoxi- 
cation. In  some  cases  this  intoxication  is  a  prominent  feature 
of  the  disorder,  in  others  it  is  subordinate  to  other  manifesta- 
tions of  the  disease ;  and,  finally,  we  may  have  marked  altera- 
tions in  metabolism  without  evidences  of  disturbance  of  health 
(e.  g.j  cystinuria,  alkaptonuria). 

Of  the  autointoxications  due  to  the  retention  of  poisonous 
products  of  metabolism  that  should  be  excreted  from  the  body, 


UREMIA  433 

first  in  order  of  importance  stand  uremia  and  cholemia  (the 
latter  has  already  been  considered  in  connection  with  the  discus- 
sion of  Icterus,  Chap.  xvi).  Of  apparently  less  significance  are 
autointoxications  due  to  failure  of  elimination  of  gaseous  meta- 
bolic products  by  the  lungs,  and  failure  of  the  excretory  func- 
tions of  the  skin. 

UREMIA1 

The  cause  or  causes  of  the  severe,  often  fatal,  intoxication 
that  may  occur  when  the  outflow  of  urine  is  completely  checked, 
or  when  it  is  qualitatively  and  quantitatively  altered  for  long 
periods  of  time,  have  not  yet  been  definitely  determined.  As 
the  kidney  seems  to  be  the  chief  organ  for  the  removal  of  the 
products  of  nitrogenous  metabolism,  it  is  naturally  assumed 
that  uremia  is  the  result  of  a  retention  of  these  products,  but  as 
yet  it  has  not  been  ascertained  which  of  the  many  products  is 
responsible,  and,  indeed,  there  are  very  good  reasons  for  question- 
ing if  the  substances  present  in  normal  urine  do  or  can  cause 
uremia  when  their  elimination  by  the  kidney  is  defective.  There 
is  no  question  but  that  the  urine  contains  toxic  substances. 
Among  them  are  the  salts  of  potassium,  which,  however,  can- 
not alone  explain  all  the  urinary  toxicity,  for  the  symptoms 
produced  by  the  injection  of  urine  are  different  from  those  pro- 
duced by  potassium  salts,  and  it  has  been  found  that  the  inor- 
ganic constituents  (ash)  of  urine  are  less  poisonous  than  the 
entire  urine.  Furthermore,  toxic  mixtures  of  organic,  ash-free 
substances  have  been  obtained  from  normal  urine.2  Of  the 
known  normal  constituents  of  the  urine  there  are  few,  however, 
that  are  toxic  to  any  considerable  degree,  and  these  occur  in  but 
very  small  quantities.  Urea  is  generally  considered  as  almost 
absolutely  non-toxic,3  the  animal  body  withstanding  injection 
of  large  quantities  without  appreciable  injury.  Uric  acid,  the 
purin  bases,  hippuric  acid,  creatinin,  and  the  urinary  pigments 
are  all  possessed  of  very  slight  toxicity,  and  their  effects  do  not 
explain  the  manifestations  of  uremia.  Injections  of  urine  into 
animals  may  cause  more  or  less  disturbance,  but  it  is  different, 
on  the  whole,  from  the  manifestations  of  uremia.  (The  experi- 
ments of  Bouchard  and  his  school  present  such  serious  errors 

1  General  re'sume'  with  literature  by :  Honigmann,  Ergeb.  der  Pathol.,  1894 
(Bd.  1,  Abt.  2),  639;  1902  (8),  549;  Ascoli,  Vorlesungen  iiber  Uramie,  Jena, 
1903. 

2  See  Dresbach,  Jour.  Exp.  Med.,  1900  (5),  315. 

3  Herter  ascribes  more  importance  to  urea  in  uremia  than  do  many  other 
authors  (see  Johns  Hopkins  Hospital  Keports,  1900  (9),  69). 

28 


434  METABOLIC  ABNORMALITIES,   AUTOINTOXICATION 

of  technique  and  interpretation  that  they  are  now  largely  dis- 
regarded.) 

For  these  and  other  reasons,  it  is  generally  considered  that 
the  intoxication  of  uremia  is  not  due  solely  or  chiefly  to  the 
substances  that  are  normally  eliminated  in  the  urine,1  but  rather 
to  more  toxic  antecedents  of  the  nitrogenous  constituents  of  the 
urine.  Urea  represents  but  the  final  product  of  a  long  series 
of  reactions  by  which  the  huge  proteid  molecule  is  broken  up 
into  its  "  building-stones,"  the  various  amino-acids,  and  these  in 
turn  are  decomposed  in  such  a  way  that  their  NH2  groups  are 
combined  with  carbonic  acid 2  and  eliminated  as  the  diamido- 

/NH2 
compound    of   carbonic  acid,   namely  urea,  O  =  O^        .     We 

know  that  the  liver  is  able  to  accomplish  the  conversion  of 
amino-acids  to  urea,  for  it  has  been  experimentally  shown  that 
if  leucin  and  glycocoll  are  passed  through  the  vessels  of  the 
isolated  liver  they  disappear  in  part,  while  an  increased  amount 
of  urea  escapes  from  the  hepatic  veins.  It  is  probable  that  the 
liver  is  the  chief  site  of  urea  formation,  but  it  is  also  probable 
that  urea  can  be  formed  in  other  organs.  We  do  not  know, 
however,  the  intermediate  steps  by  which  the  amino-acids  of 
the  proteid  molecule  are  converted  into  urea.  It  has  been 
repeatedly  shown  that  urea  can  be  formed  from  ammonium  salts 
of  organic  acids  (including  ammonium  carbonate),  and  ammonia 
is  a  constant  product  of  autolysis,  being  characteristically  more 
abundant  as  a  product  of  autolytic  proteolysis  than  as  a  prod- 
uct of  tryptic  proteolysis ;  therefore,  one  of  the  antecedents 
of  urea  is  probably  ammonia,  which  is  somewhat  toxic  and 
especially  hemolytic.3  Another  antecedent  of  urea  is  ammonium 
carbamate,  which  stands  in  structure  intermediate  between  urea 
and  ammonium  carbonate,  as  shown  by  the  following  graphic 
formula : 

/OH  /O  — NH4                    /NH2  /NH2 

0  =  C<  0:=C<                       0  =  C<  0=C< 

X)H  \0  —  NH4                   XO  —  NH4  \NH2. 

(carbonic  acid)  (ammonium  carbonate)  (ammonium  carbamate)  (urea) 

That  ammonium  carbamate  is  probably  an  important  precursor 
of  urea  has  been  shown  particularly  through  the  results  of 
studies  of  dogs  with  Eck's  fistula,4  which  consists  of  a  fistula 

1  See  Bradford,  Practitioner,  1901  (67),  507. 

2  Arginin  alone  of  all  the  amino-acids  is  known  to  split  ofi  urea  directly 
from  its  molecule. 

3  Concerning  the   toxicity  of  ammonium   salts   see   Rachford  and  Crane, 
Medical  News,  1902  (81),  778. 

4  See  Hahn,  Massen,  Nencki,  and  Pawlow,  Arch.  f.  exp.  Path.  u.  Pharm., 
1893  (32),  161. 


UREMIA  435 

between  the  portal  vein  and  the  inferior  vena  cava,  the  blood 
from  the  portal  system  then  passing  directly  into  the  general 
circulation  without  first  passing  through  the  liver.  In  such 
animals  the  urine  becomes  poor  in  urea  and  relatively  rich  in 
ammonium  carbamate.  At  the  same  time,  the  dogs  show  severe 
symptoms  of  intoxication  from  which  they  die,  and  which  are 
similar  to  the  symptoms  that  follow  intravenous  injection  of 
ammonium  carbamate.  Ammonium  carbamate,  being  a  sub- 
stance of  considerable  toxicity  l  when  free  in  the  blood,  it  has, 
therefore,  been  quite  widely  considered  that  it  may  be  an 
important  factor  in  the  production  of  uremic  symptoms.  On  the 
other  hand,  it  seems  most  probable  that  the  condition  of  uremia 
does  not  depend  upon  one  but  upon  many  various  and  vary- 
ing substances.  Clinically  the  symptoms  of  uremia  in  different 
cases  are  widely  different ;  thus,  if  uremia  is  due  to  complete 
suppression  of  urine  through  mechanical  obstruction,  the  symp- 
toms are  quite  different  from  those  observed  in  the  uremia 
following  a  chronic  nephritis ;  drowsiness,  weakness  of  heart 
action,  and  syncope  being  the  chief  manifestations  of  obstruc- 
tive uremia,  the  convulsions  and  other  manifestations  of  nervous 
irritation  characteristic  of  uremia  in  chronic  nephritis  being 
absent. 

Chemical  Change  in  Uremia. — The  attempts  to  isolate 
from  the  blood  and  organs  of  uremic  patients  or  animals  toxic 
substances  that  explain  the  manifestations  of  uremia  have  thus 
far  failed.2  That  there  is  an  actual  retention  of  organic  sub- 
stances in  the  blood  in  uremia  is  shown  conclusively,  however, 
by  the  studies  of  the  physicochemical  properties  of  the  blood. 
It  has  been  repeatedly  found  that  in  uremia  the  freezing-point  of 
the  blood  is  reduced  markedly  below  the  normal;3  instead  of 
the  normal  depression  of  0.55°— 0.57°  the  freezing-point  is 
usually  reduced  more  than  — 0.60°,  and  sometimes  as  much 
as  — .75°,  wThich  shows  that  the  number  of  molecules  in 
the  blood  is  increased.4  At  the  same  time,  the  electrical 
conductivity  may  not  be  at  all  increased  (Bickel5),  but  may 
even  be  reduced  ;  and  as  the  electrical  conductivity  of  the 
blood  depends  upon  the  number  of  dissociable  molecules, 
chiefly  inorganic  salts,  these  are  evidently  not  increased. 
Therefore,  the  increased  number  of  molecules  must  represent 

1  See  Bickel,  "  Exp.  Untersuch.  iiber  Cholaemie,"  Wiesbaden,  1900. 
2SeeCouve"e,  Zeit.  klin.  Med.,  1904  (54),  311. 

3SeeTieken,  Araer.  Med.,  1905  (10),  pp.  393,  567,  and  822;  complete  liter- 
ature. 

4  See  table  of  freezing  points  of  blood  and  effusions  on  page  298. 
5Deut.  med.  Woch.,  1902  (28),  501. 


436   METABOLIC  ABNORMALITIES,   A  UTOINTOXICATION 

an  excess  of  organic  molecules  that  dissociate  but  little  if 
at  all,  and  hence  are  not  conductors  of  electricity.  Some 
authors,  indeed,  have  ascribed  uremia  to  the  increased  osmotic 
pressure  of  the  blood  from  the  retained  molecules,  but  this  is 
improbable,  according  to  Strauss,1  who  found  that  a  marked 
increase  in  molecular  concentration  may  occur  without  uremia, 
and  that  we  may  have  a  severe  uremia  without  increased 
osmotic  pressure.2 

That  organic  nitrogenous  bodies  accumulate  in  the  blood  in 
nephritis  has  been  repeatedly  demonstrated.  Strauss  found 
that  the  non-proteid  nitrogen  of  the  blood,  which  normally 
amounts  to  20-35  mg.  per  100  c.c.  of  blood,  shows  a  slight  in- 
crease in  chronic  parenchymatous  nephritis,  to  about  40  mg.  j 
and  in  interstitial  nephritis,  a  large  increase,  the  total  amount 
averaging  85  mg.,  being  especially  high  when  uremia  is  present. 
Urea  is  demonstrably  increased  under  the  same  conditions,  as 
also  is  the  ammonia  nitrogen,  especially  in  uremia.  Erben3 
has  studied  the  variations  in  the  normal  components  of  the 
blood  during  nephritis,  and  found  the  albumin  generally  de- 
creased in  proportion  to  the  globulin,  especially  in  the  case  of 
parenchymatous  nephritis ;  lecithin  and  calcium  are  also  de- 
creased. The  decrease  in  red  corpuscles  and  hemoglobin  in 
nephritis  is  a  well-known  feature.  By  the  precipitin  reaction  it 
has  been  shown  that  the  globulin  of  nephritic  urine  is  derived 
from  the  serum,  and  not  directly  from  the  proteids  of  the  food. 
Rumpf 4  has  analyzed  the  organs  as  well  as  the  blood  in  nephritis, 
and  found  a  distinct  retention  of  organic  substances  in  both  the 
blood  and  organs ;  sodium  chloride  is  usually  increased,  as  also 
are  the  other  inorganic  salts,  which  are  probably  partly  bound 
in  organic  combination  with  the  tissues.  (See  "  Retention  of 
Chlorides  in  Edema,"  p.  293.)  The  reduction  of  the  alkalinity 
of  the  blood,  observed  by  v.  Jaksch  and  others  in  uremia,  is 
attributed  by  Gottheiner 5  to  the  presence  of  abnormally  large 
quantities  of  lactic  acid  in  the  blood.  Orlowski 6  found  that 
an  accumulation  of  acids  occurs  in  uremia,  but  not  until  just 
before  death,  and,  therefore,  the  reduction  of  blood  alkalinity  is 
not  the  cause,  but  an  accompaniment  of  the  uremia.  Further- 

xDie  chronischen  Nierenentziindungen,  etc. ,  Berlin,  1902. 

2  Stern  (  Med.  Kecord,  1903  (63),  121)  )  notes  that  the  electrical  conductiv- 
ity is  reduced  by  the  presence  of  excessive  quantities  of  non-electrolytes  in 
uremia,  and  regards  this  lowered  conductivity  as  a  factor  of  some  possible  im- 
portance. 

»Zeit.  klin.  Med.,  1903  (50),  441 ;  1905  (57),  39. 

*  Munch,  med.  Woch.,  1905  (52),  393. 

6Zeit.  klin.  Med.,  1897  (33),  315. 

6Zentr.  f.  Stoflwechsel  u.  Verdauungskr. ,  1902  (3),  123. 


UREMIA  437 

more,  in  other  diseases  a  corresponding  or  greater  reduction  in 
alkalinity  may  occur  without  uremia.  The  development  of  this 
terminal  acidity,  together  with  the  finding  of  albumose  in  the 
blood  of  a  nephritic  by  Schumm,1  suggests  the  probability  of 
active  autolytic  processes  occurring  in  uremia.  Neuberg  and 
Strauss2  have  also  found  glycocoll  in  considerable  quantities 
(1.5  per  mille)  in  the  blood-serum  of  a  uremic  patient  and  in 
the  blood  of  nephrectomized  rabbits. 

The  Cause  of  Uremia. — Putting  all  the  known  facts 
together,  we  find  the  weight  of  evidence  indicating  that  uremia 
is  due  to  poisoning  with  organic  substances,  probably  ante- 
cedents of  urea,  but  of  unknown  nature.  The  poison  or  poisons 
may  be  sufficiently  concentrated  to  cause  structural  alterations 
in  the  cortical  ganglion-cells  (chromatolysis)  which  have  been 
repeatedly  found  in  uremia.  As  yet,  however,  we  are  com- 
pletely in  the  dark  as  to  whether  the  substances  causing  the 
uremia  are  such  well-known  antecedents  of  urea  as  ammonium 
carbamate  and  other  ammonium  salts,  or  some  quite  specific  and 
unfamiliar  nitrogenous  substances  which  arise  in  the  cells  as  the 
result  of  the  action  of  accumulated  decomposition-products  of 
the  proteids.  To  account  for  an  accumulation  of  the  antecedents 
of  urea  we  do  not  need  to  assume  a  perversion  of  metabolism 
as  the  cause,  if  we  appreciate  that  the  various  reactions  of  met- 
abolism, being  due  to  catalytic  agents,  go  on  to  the  point  of 
establishing  a  chemical  equilibrium.  If  for  any  cause  the 
kidneys  cannot  excrete  all  the  urea  formed,  its  accumulation  in 
the  blood  and  tissues  will  necessarily  lead  to  a  blocking  of  the 
steps  of  urea  formation,  and  a  corresponding  accumulation  of  the 
antecedents  of  urea  in  the  body.  On  the  other  hand,  it  is  to  be 
borne  in  mind  that  the  decrease  in  elimination  of  nitrogen  in 
nephritis  is  not  so  great  as  is  ordinarily  assumed,  the  popular 
error  being  due  to  the  fact  that  most  clinical  estimations  of 
urinary  nitrogen  are  based  on  the  determination  of  the  urea 
alone.  In  nephritis  the  urea  may  constitute  a  much  smaller 
proportion  of  the  total  urinary  nitrogen  than  in  health,  on  ac- 
count of  the  relatively  greater  proportion  of  nitrogen  eliminated 
in  other  forms.  According  to  numerous  observers,  particularly 
the  Italians,  the  proportion  of  these  intermediary  nitrogenous 
bodies  may  be  increased  in  the  blood,  even  when  the  urinary 
nitrogen  is  normal  in  amount,  and  if  this  statement  is  correct, 
then  presumably  abnormal  metabolism,  rather  than  defective 
renal  elimination,  is  primary ;  in  which  case  the  renal  lesions 

1  Hofmeister's  Beitr.,  1903  (4),  453. 

2  Berl.  klin.  Woch.,  1906  (43),  258. 


438  METABOLIC  ABNORMALITIES,  AUTOINTOXICATION 

may  have  been  produced  secondarily  by  the  products  of  the 
abnormal  metabolism. 

While  admitting  the  preponderating  importance  of  toxic 
organic  substances  as  the  cause  of  uremia,  we  cannot  dismiss  as 
altogether  unimportant  the  changes  in  osmotic  pressure  in  the 
blood  and  tissue  fluids,  even  although  it  has  been  shown  by 
Strauss  and  others  that  there  is  no  constant  relation  be- 
tween the  osmotic  pressure  of  the  blood  and  the  uremic  attack. 
It  still  seems  quite  possible  that  the  hyperosmotic  condition  of 
the  fluids  in  the  brain  is  the  determining  factor  in  some  uremic 
attacks.  Neither  can  we  entirely  dismiss  the  edema  of  the 
brain  and  meninges  that  is  associated  with  this  hypertonicity, 
from  the  possible  factors  in  the  production  of  uremia.  The 
"  wet  brain  "  of  the  uremic  is  too  frequent  an  autopsy  finding 
to  be  without  importance,  and  clinicians  have  repeatedly  noted 
a  favorable  effect  from  spinal  puncture  in  uremia,  following 
the  escape  of  a  fluid  under  apparently  abnormally  high  pressure.1 

The  Internal  Secretion  of  the  Kidney. — Another  possible 
factor  in  uremia  is  the  hypothetical  internal  secretion  of  the 
kidney.  Bradford,2  through  an  extensive  experimental  study 
of  the  effects  of  partial  resection  of  the  kidney  tissue,  found 
that  if  three-quarters  of  the  total  kidney  tissue  be  removed  (in 
dogs)  death  occurs  with  profound  tissue  wasting  and  asthenia, 
which  is  associated  with  an  elimination  of  more  urea  and  water 
than  a  normal  animal  passes  with  two  complete  kidneys.  The 
fragment  of  kidney  left  is  able  to  excrete  amounts  of  urea  far 
larger  than  those  usually  excreted,  as  is  shown  by  giving  the 
animals  considerable  quantities  of  an  exclusively  meat  diet.  Of 
particular  importance  is  the  fact  that  the  amount  of  nitrogenous 
extractives  (non-proteid  nitrogen)  in  the  blood  and  tissues,  especi- 
ally the  muscles,  is  much  greater  than  in  normal  animals,  even 
when  the  nitrogen  excretion  is  above  normal ;  which  indicates 
that  loss  of  renal  tissue  results  in  excessive  proteid  katabolism, 
and  suggests  that  the  kidneys  have  an  important  function  in 
regulating  proteid  metabolism  through  the  production  of  an 
internal  secretion  with  inhibitory  effect  on  metabolism.  In 
accordance  with  this,  Yitzou 3  claims  to  have  demonstrated  that 
the  blood  from  the  renal  vein  contains  substances  which  decidedly 
reduce  the  severity  of  uremia  in  experimental  animals.  If  this 
contention  is  true,  there  exists  the  possibility  that  in  interstitial 
nephritis  the  loss  of  renal  tissue  may  cause  a  deficiency  in  an 

lSee  Willson,  Jour.  Amer.  Med.  Assoc.,  1904  (43),  1019. 

2  Jour,  of  Physiol.,  1899  (23),  415. 

3  Jour.  Phys.  et  Path.  Gen.,  1901  (3),  901  and  926. 


ECLAMPSIA  439 

internal  secretion  which  depresses  proteid  katabolism,  and  thus 
leads  to  an  excessive  formation  of  nitrogenous  substances  in  the 
tissues  and  their  accumulation  in  the  blood. 

ECLAMPSIA1 

In  many  respects  eclampsia  resembles  uremia ;  so  much  so, 
indeed,  that  Frerichs  and  others  have  referred  to  eclampsia  as 
"  puerperal  uremia."  Considering  it  as  a  simple  uremia  occur- 
ring in  pregnancy,  uremia  and  eclampsia  have  in  common  the 
constant  occurrence  of  renal  disturbance  with  albuminuria  and 
decreased  elimination  of  urea,  and  also  violent  convulsions  and 
profound  coma  terminating  in  death.  On  the  other  hand, 
eclampsia  differs  greatly  from  uremia  in  the  anatomical  changes 
observed  in  the  organs  of  the  body  other  than  the  kidneys  ; 
these  are  of  such  a  nature  that  in  some  cases  it  becomes 
difficult  to  distinguish  eclampsia  from  acute  yellow  atrophy  of 
the  liver,  while  in  other  cases  the  picture  resembles  that  of  a 
profound  bacterial  intoxication,  so  that  numerous  authors  have 
urged  that  eclampsia  is  the  result  of  a  bacterial  infection.  At 
the  present  time  the  cause  of  puerperal  eclampsia  is  quite 
unknown,  but  there  is  a  decided  tendency  to  assume  that 
poisonous  substances  are  developed  in  the  placenta  or  fetus,  or 
are  formed  in  the  body  as  a  reaction  of  the  maternal  organism 
to  the  foreign  fetal  elements.  These  theories  will  be  discussed 
after  considering  the  known  facts  concerning  the  chemical 
changes  of  the  disease  that  have  been  reported  by  various 
observers. 

Chemical  Changes  in  Eclampsia. —  Urinary  changes 
are  practically  invariably  present,  and  usually  they  are  profound, 
although  there  are  no  known  characteristic  qualitative  or  quan- 
titative differences  from  the  urinary  changes  of  puerperal 
albuminuria  without  eclampsia.  Proteids  are  abundant,  includ- 
ing a  large  proportion  of  globulin,  decreasing  rapidly  after 
delivery  as  a  rule.  The  urea  is  usually  very  low,  but  generally 
increases  with  great  rapidity  after  delivery,  until  two  or  three 
times  the  normal  amount  is  passed  per  day ;  as  urea  and 
ammonia  do  not  seem  to  be  increased  in  the  blood,  this  indicates 
that  during  eclampsia  there  is  an  accumulation  of  the  precursors 
of  urea  in  the  system  (Sikes).  There  is  an  excessive  elimina- 
tion of  nitrogen  in  the  form  of  ammonia,  which  seems  to  be 
due  to  the  formation  of  abnormal  quantities  of  sarcolactic  and 

1  A  thorough  review  of  the  literature  is  given  by  Sikes  in  The  Practitioner, 
1905  (74),  pp.  478  and  642,  with  complete  bibliography.  Only  more  recent 
references  will  generally  be  cited  in  the  text. 


440  METABOLIC  ABNORMALITIES,   AUTOINTOXICATION 

other  organic  acids  in  the  body,  which  are  combined  with 
ammonia  in  the  blood  and  eliminated  in  the  urine.1  This  fact 
has  led  many  to  look  with  favor  upon  the  idea  that  eclampsia  is 
due  to  an  acid  intoxication.  Other  nitrogenous  urinary  constit- 
uents may  also  be  increased,  so  that  the  relative  proportion  of 
nitrogen  eliminated  as  urea  is  often  greatly  reduced.  The 
proportion  of  sulphur  eliminated  in  an  unoxidized  form,  as 
compared  with  that  eliminated  as  SO4,  is  much  greater  than 
normal.  These  findings  all  indicate  that  oxidation  within  the 
body  is  impaired. 

Numerous  writers  have  studied  the  toxicity  of  the  urine  in 
eclampsia,  but  the  earlier  investigations  were  conducted  in  such 
a  manner  that  the  results  are  practically  worthless.  More  recent 
studies  by  Volhardt,  Schumacher,  and  Van  der  Bergh  yield  no 
evidence  that  the  urine  shows  any  actual  differences  in  toxicity 
whether  from  normal,  pregnant,  or  eclamptic  women.  . 

Analyses  of  the  blood  have  given  widely  differing  results, 
some  finding  an  increase  in  urea,  while  others  have  failed  to 
observe  such  increase  (the  latter  including  the  more  recent 
observations).  Likewise  the  statements  concerning  the  quantity 
of  ammonia  in  the  blood  are  at  variance,  Zweifel  holding  that 
neither  urea  nor  ammonia  is  increased.  The  decrease  in  the 
alkalinity  of  the  blood  observed  by  Zangemeister  and  others 
has  been  ascribed  to  the  formation  of  sarcolactic  acid  by  Zweifel,2 
who  failed,  however,  to  find  an  excess  of  CO2,  or  to  detect 
oxy butyric  acid  or  oxalic  acid  in  the  blood.  As  to  the  blood 
proteids,  fibrin  has  been  found  increased  by  Kolman  and  by 
Dienst,  while  Schmidt  found  a  relative  increase  in  the  globulin. 
Sikes  concludes  that  the  statements  to  be  found  in  the  literature 
concerning  the  toxicity  of  the  blood  in  eclampsia  leave  nothing 
proved  concerning  this  point. 

Theories  as  to  Etiology. — The  anatomical  changes  of 
eclampsia  are  such  as  to  leave  little  or  no  room  for  doubt  that 
there  is  a  severe  intoxication  with  poisons  that  have  a  markedly 
toxic  effect  upon  all  the  organs  of  the  body,  thus  differing  from 
the  toxic  materials  at  work  in  uremia,  which  seem  to  affect 
chiefly  the  central  nervous  system.  Repeated  bacteriological 
and  histological  studies  have  failed  to  demonstrate  that  infection 
with  either  vegetable  or  animal  parasites  is  the  cause,  and 
clinical  observations  do  not  support  such  a  hypothesis.  The 
association  of  the  condition  with  pregnancy,  and  particularly 
the  rapid  improvement  that  follows  the  removal  of  the  contents 

1  See  Zweifel  and  Lockmann,  Munch,  med.  Woch.,  1906  (53),  297. 

2  Arch.  f.  Gyn.,1905  (76),  537. 


ECLAMPSIA  441 

of  the  uterus,  almost  compels  us  to  admit  that  the  causative 
agent  is  produced  by  the  fetus  or  the  placenta.  Some  investi- 
gators (Politi,  Liepmann)  believe  that  they  have  found  a  greater 
degree  of  toxicity  in  extracts  from  the  placentas  from  eclamptic 
than  from  normal  women.  We  have  no  approximate  ideas 
as  to  the  nature  of  the  supposed  toxic  substances,  except  that 
Zweifel,1  who  is  the  leading  exponent  of  the  idea  that  eclampsia 
is  an  acid  intoxication,  believes  that  the  fetus  produces  abnormal 
quantities  of  lactic  acid  which  is  the  cause  of  the  maternal 
intoxication.  In  support  of  this  view  he  reports  the  finding  in 
eclampsia  of  lactic  acid  in  blood  from  the  umbilical  vein  in  much 
greater  quantities  than  in  the  maternal  blood,  and  in  still  greater 
quantities  in  the  placenta.  It  seems  improbable,  however,  that 
the  severe  anatomical  changes  and  the  convulsive  manifestations, 
so  different  from  the  conditions  observed  in  ordinary  acid  intox- 
ications, can  be  due  to  sarcolactic  acid  alone,  especially  when  in 
such  minute  quantities  as  it  is  found  in  the  blood  of  eclamptics. 

The  Placenta  as  a  Source  of  Intoxication. — Histologists 
having  frequently  observed  placental  cells  in  the  blood  and 
vessels  of  eclamptic  patients,  it  has  been  suggested  that  multi- 
ple capillary  emboli  of  placental  cells,  detached  from  the  chorionic 
villi  and  forced  into  the  placental  circulation,  cause  the  manifes- 
tations of  the  disease ;  this  theory  is  entirely  inadequate,  how- 
ever, to  explain  all  the  features  of  eclampsia.  Related  to  this 
hypothesis  is  the  idea  that  the  placental  tissues,  being  foreign  to 
the  maternal  organism  in  so  far  as  they  are  derived  from  the 
ovum,  give  rise  to  the  production  of  antibodies  (syncytiolysins) 
by  the  mother,  which  are  toxic  for  pregnant  animals  (Ascoli), 
and  which  may  have  to  do  with  eclampsia  in  some  unknown 
way.  In  any  case,  antiserum  for  placental  tissue  has  been 
repeatedly  prepared  (Weichardt,  Scholten  and  Veit,2  Opitz3). 
Possibly  the  foreign  tissues  are  toxic  to  the  maternal  organism, 
or  form  toxic  substances  during  their  solution  (Weichardt),  and 
a  failure  to  develop  such  antibodies  as  have  been  obtained 
experimentally  leaves  the  mother  unprotected  from  these  toxic 
substances.  Up  to  the  present  time,  however,  this  phase  of 
the  study  of  the  pathogenesis  of  eclampsia  has  yielded  little 
besides  interesting  but  contradictory  hypotheses.4 

Liepmann  5  has  reported  the  finding  of  a  considerable  degree 
of  toxicity  in  eclamptic  placentas ;  the  poisonous  substance, 

1  Loc.  eit. 

2Zeit  f.  Geb.  u.  Gyn.,  1903  (49),  210. 

3Deut.  med.  Woch.,  1903  (29),  597. 

4 See  review  by  Wormser,  Munch,  med.  Woch.,  1904  (51),  7  and  2285. 

6  Munch,  med.  Woch.,  1905  (52),  687  and  2484. 


442  METABOLIC  ABNORMALITIES,  AUTOINTOXICATION 

which  is  extremely  labile,  being  firmly  united  to  the  proteid 
molecule,  and  as  yet  not  successfully  isolated. 

The  Fetus  as  a  Source  of  Intoxication. — A  reasonable 
view  of  the  cause  of  eclampsia  is  that  it  is  initiated  by  the 
excessive  products  of  metabolism  thrown  into  the  blood  of 
the  mother,  both  from  the  fetus  and  from  her  own  overactive 
tissues  ;  these  cause  injury  to  the  kidneys,  leading  to  a  further 
retention,  or  injure  the  liver  so  that  the  normal  metabolic 
processes  of  that  organ  (particularly  oxidation)  cannot  be 
carried  on ;  or,  perhaps  more  often,  both  liver  and  kidney  as 
well  as  other  organs  are  injured.  In  this  way  a  vicious  circle 
is  established  which  rapidly  leads  to  an  overwhelming  of  the 
maternal  system  with  toxic  products  derived  from  both  her  own 
and  the  fetal  tissues.  It  must  be  admitted,  however,  that  the 
rapid  improvement  that  so  often  follows  removal  of  the  products 
of  conception  indicates  strongly  that  the  poisonous  substances 
arise  chiefly,  if  not  exclusively,  in  the  fetus  or  the  placenta. 
But,  as  Liepmann  points  out,  the  child  shows  relatively  little 
evidence  of  intoxication,  while,  on  the  other  hand,  eclampsia 
may  develop  after  delivery  of  the  fetus,  which  facts  speak  in 
favor  of  the  place  of  the  origin  of  the  poison  being  the  placenta 
and  not  the  fetus.  Especially  important  in  this  connection  is 
the  observation  of  a  case  of  eclampsia  by  Hitschmann l  in  a 
patient  with  a  hydatid  mole  and  no  fetus.2 

The  Thyroid  in  Eclampsia. — In  view  of  the  mystery  sur- 
rounding the  cause  and  effect  of  the  enlargement  of  the  thyroid 
during  pregnancy,  it  is  not  strange  that  the  suggestion  has  been 
made  that  the  enlargement  is  for  the  purpose  of  neutralizing 
the  excessive  amounts  of  toxic  materials  in  the  maternal  blood, 
and  that  failure  of  this  enlargement  is  responsible  for  eclampsia. 
In  support  of  this  idea  Lange3  states  that  absence  of  the 
normal  thyroid  enlargement  is  usual  in  eclampsia,  and  Fruhins- 
holz  and  Jeandelize4  note  the  frequency  of  eclampsia  in 
myxedematous  women. 

Summary. — Most  of  the  facts  at  hand  speak  against  the 
idea  that  one  definite  chemical  substance  is  responsible  for 
the  anatomical  changes  and  symptomatic  manifestations  of 
eclampsia.  More  probably  there  are  present  not  only  the 

1  Cent.  f.  Gyn.,  1904  (28),  1089. 

2Dienst  (Cent.  f.  Gyn.,  1905  (29),  353)  has  advanced  the  proposition  that 
in  eclampsia  there  is  a  mixture  of  the  heterogeneous  fetal  blood  with  that  of 
the  mother,  based  on  the  finding  of  direct  communication  between  the 
maternal  and  fetal  circulation  in  eclampsia. 

3  Zeit.  f.  Geb.  u.  Gyn.,  1899  (40),  34. 

*Presse  MeU,  1902  (10),  1023. 


ACUTE  YELLOW  ATROPHY  OF  THE  LIVER          443 

poisonous  substances  that  initiate  the  tissue  changes,  but  also 
toxic  substances  that  accumulate  because  of  the  disorganiza- 
tion of  the  liver  and  kidney  cells,  and  which  are  possibly 
similar  to  the  toxic  substances  most  prominent  in  uremia 
and  in  acute  yellow  atrophy,  for  eclampsia  seems  to  stand 
intermediate  between  these  two  diseases,  encroaching  upon 
the  characteristics  of  each.  Acid  intoxication,  which  un- 
doubtedly exists  to  a  greater  or  less  degree  in  some  cases  of 
eclampsia,  is  probably  not  usually  the  chief  cause  of  the  clinical 
manifestations  of  the  disease.  The  finding  of  minute  quantities 
of  lactic  acid  in  the  blood,  urine,  and  in  the  cerebrospinal  fluid 
(Fiith  and  Lockemann x )  is  perhaps  not  of  great  significance, 
for,  as  Wolf2  rightly  insists,  similar  amounts  may  be  found  in 
other  conditions  associated  with  convulsions  and  partial  as- 
phyxia, or  in  partial  starvation,  such  as  results  from  the  vomit- 
ing of  pregnancy.  To  be  sure,  Zweifel  states  that  lactic  acid 
may  be  found  in  the  urine  and  blood  before  the  eclamptic 
seizures  have  appeared,  but,  in  any  case,  the  anatomical  changes 
and  clinical  manifestations  cannot  be  explained  as  due  to  the 
action  of  the  trifling  quantities  of  sarcolactic  acid  found  in  the 
blood  of  these  patients.  The  excretion  of  these  organic  acids, 
as  well  as  the  large  proportion  of  unoxidized  sulphur  in  the 
urine,  indicates  that  incomplete  oxidation  is  an  important  feature 
of  eclampsia,  and  under  such  conditions  a  large  number  of 
imperfectly  known  toxic  substances  may  accumulate  in  the 
blood  and  tissues.  The  defective  oxidation  is  probably  the 
result  of  the  injury  to  the  liver-cells,  which  have  such  a  promi- 
nent oxidizing  function. 

ACUTE  YELLOW  ATROPHY  OF  THE  LIVER 

In  this  condition  there  is  presented  a  striking  picture  of 
autolysis,  in  that  a  large  parenchymatous  organ  undergoes  a 
rapid  reduction  of  size  because  of  a  solution  of  its  structural 
elements,  while  at  the  same  time  products  of  proteid  digestion 
(leucin,  tyrosin,  etc.)  appear  free  in  the  liver,  the  blood,  and  the 
urine.  Because  of  these  prominent  features  and  their  relation 
to  the  questions  of  metabolism  in  general,  and  the  function  of 
the  liver  in  particular,  acute  yellow  atrophy  of  the  liver  has 
been  the  object  of  much  greater  interest  and  investigation  than 
its  clinical  importance  would  warrant,  for  it  is  a  rare  disease, 
there  probably  being  but  about  500  cases  reported  in  the  litera- 
ture, according  to  Best's  figures.3 

1  Cent.  f.  Gyn.,  1906,  p.  41.  2  New  York  Med.  Jour.,  1906  (83),  813. 

3  Thesis,  University  of  Chicago,  1903. 


444  METABOLIC  ABNORMALITIES,   AUTOINTOXICATION 

The  etiology  of  the  disease  is  quite  unknown,  but  it  is  very 
probably  not  a  specific  one,  for  we  find  that  numerous  forms  of 
intoxication  may  lead  to  a  condition  closely  resembling  acute 
yellow  atrophy,1  particularly  phosphorus  poisoning,  chloroform 
poisoning,  puerperal  eclampsia,  and  some  cases  of  septicemia 
(especially  with  the  streptococcus 2),  arsenic  poisoning,  and 
mushroom  poisoning.  It  seems  probable  that  any  poison  which 
does  not  directly  cause  death,  but  which  causes  a  severe  injury 
to  the  liver-cells  without  at  the  same  time  destroying  the  auto- 
lytic  enzymes,  so  that  the  cells  die  and  undergo  rapid  autolysis, 
may  produce  a  condition  identical  with  or  similar  to  acute  yel- 
low atrophy  (Wells  and  Bassoe 3).  In  the  typical  cases  of  the 
disease,  of  "idiopathic"  origin,  the  poisonous  agent  probably 
comes  from  the  alimentary  canal,  as  indicated  by  a  preliminary 
period  of  gastro-intestinal  disturbance  that  usually  precedes 
the  onset  of  the  disease,  and  secondly  by  the  fact  that  the  liver 
seems  to  receive  the  chief  effect  of  the  poison.  Whether  these 
hypothetical  poisons  are  produced  by  abnormal  fermentation  and 
putrefaction  in  the  alimentary  tract,  or  by  a  specific  organism 
elaborating  its  poison  in  this  location,  is  quite  unknown.  Bac- 
teriological studies  of  the  disease  have  so  far  given  inconstant 
and  non-instructive  results.  In  the  countries  where  phosphorus 
poisoning  is  common  (especially  Austria)  there  has  been  found 
much  difficulty  in  distinguishing  in  many  cases  the  results  of 
phosphorus  poisoning  from  acute  yellow  atrophy  of  the  liver, 
and  many  have  contended  that  there  is  no  real  difference ;  i.  e., 
that  phosphorus,  as  well  as  unknown  poisons,  may  cause  acute 
yellow  atrophy.  The  present  trend  of  opinion,  however,  seems 
to  favor  the  view  that  there  is  a  primary  liver  atrophy  which  is 
different  from  that  caused  by  phosphorus  or  other  known 
poisons  in  several  essential  respects.4 

Phosphorus  Poisoning. — Between  phosphorus  poisoning 
and  "primary "  hepatic  atrophy  the  following  chief  differences 
may  be  discerned  :  Phosphorus  produces  a  general  injurious  effect 
upon  all  the  organs  of  the  body,  the  liver  merely  showing  the 
most  marked  anatomical  changes,  which  at  first  consist  of  a 
fatty  metamorphosis  of  the  liver,  due  to  migration  of  the  body  fat 

1  It  is  to  be  borne  in  mind  that  the  color  is  yellow  only  during  the  earlier 
stages,  "  red  atrophy,"  occurring  later,  but  the  name  acute  "  yellow  atrophy " 
has  come  through  usage  to  apply  to  the  disease  as  a  whole. 

2  Babes,  Ann.  Inst.  Path.  Bucarest,  vol.  6. 

3  Jour.  Amer.  Med.  Assoc.,  1904  (44),  685. 

4  See  Anschiitz,  Arb.  a.  d.  Path.  Inst.  Tubingen,  1902  (3),  230;  Paltauf, 
Verb.  Deut.  Path.  Gesell.,  1903  (5),  91;  Kiess,  Berl.  klin.  Woch.,  1905  (42), 
No.  44a,  p.  54. 


ACUTE  YELLOW  ATROPHY  OF  THE  LIVER         445 

from  the  fat  deposits  into  the  injured  cells  (Rosenfeld,  Taylor) ; 
subsequently  the  liver-cells  disintegrate,  the  cytoplasm  being 
affected  before  the  nucleus,  and  the  liver  may  become  smaller 
than  normal,  although  it  is  usually  enlarged  because  of  the  fat 
deposition.  Typical  acute  yellow  atrophy  is  characterized  by 
an  early  necrosis  of  a  large  proportion  of  the  liver-cells,  the 
nucleus  becoming  unstainable  while  the  cytoplasm  is  still  little 
altered  in  appearance,  and  fatty  changes  play  a  subordinate  role 
or  are  absent.  As  Anschiitz  says,  the  poison  seems  to  strike  at 
the  life  of  the  cell,  its  nucleus,  while  phosphorus  attacks  the 
cytoplasm.  Furthermore,  the  poison  of  yellow  atrophy  seems 
to  be  very  specific,  for  it  attacks  the  other  organs  of  the  body 
almost  not  at  all,  and  within  the  liver  it  affects  only  the  hepatic 
cells  proper,  while  the  bile-duct  epithelium  and  the  stroma  cells 
are  so  little  injured  that  they  are  able  to  proliferate  greatly,  this 
proliferation  being  a  prominent  feature.  There  are  also  clinical 
and  chemical  differences  that  will  be  discussed  later,  but  yet,  on 
the  whole,  the  resemblances  of  yellow  atrophy  and  phosphorus 
poisoning  are  so  great  that  we  have  obtained  much  information 
concerning  the  former  by  means  of  experimental  studies  of 
phosphorus  poisoning. 

Delayed  Chloroform  Poisoning. — After  chloroform  narcosis 
there  occasionally  develops  a  severe  intoxication,  with  clinical 
and  anatomical  findings  very  similar  to  acute  yellow  atrophy  and 
phosphorus  poisoning  ; l  in  point  of  the  fatty  changes  the  cases 
usually  resemble  more  the  phosphorus  poisoning.  Some  cases 
of  puerperal  eclampsia  also  present  such  profound  liver  changes 
that  they  are  distinguished  as  eclampsia  chiefly  on  the  basis  of 
the  convulsive  manifestations,  rather  than  on  the  ground  of 
anatomical  changes.  So,  too,  the  hepatic  changes  in  certain  sep- 
ticemias  may  resemble  those  of  acute  yellow  atrophy  to  a  greater 
or  less  degree. 

Summary  of  Views  on  Btiology. — From  a  review  of 
the  literature  and  the  study  of  a  few  cases,  the  writer  has 
reached  the  following  understanding  of  the  condition  described 
as  acute  yellow  atrophy  of  the  liver  :  The  "  atrophy  "  is  due 
entirely  to  autolysis  of  necrotic  liver-cells  by  their  own  enzymes. 
In  the  most  typical  cases  of  "  primary  "  or  "  idiopathic  "  yellow 
atrophy  we  have  to  do  with  a  poison  having  a  very  specific 
effect  on  the  liver-cells,  which  destroys  their  "  life  "  (i.  e.,  stops 
synthetic  activities)  without  injuring  their  intracellular  proteo- 
lytic  enzymes,  and  consequently  autolysis  occurs  ;  as  the  poison 

1  Complete  review  and  literature  by  Be  van  and  Favill,  Jour.  Amer.  Med. 
Assoc.,  1905  (45),  691. 


446   METABOLIC  ABNORMALITIES,   AUTOINTOXICATION 

affects  other  organs  but  little,  the  necrosis  and  autolysis  continue 
until  there  is  so  much  loss  of  liver  function  that  systemic  poison- 
ing results  from  the  hepatic  insufficiency  and  from  the  resulting 
accumulation  of  poisonous  products  of  incomplete  metabolism. 
The  patient  dies  from  this  poisoning,1  and  the  liver  is  found  at 
autopsy  to  have  decreased  by  from  one-third  to  one-half  or  more 
in  its  volume.  This  great  change  would  not  be  possible  if  the 
poisons  affected  the  heart,  kidneys,  or  brain  as  much  as  they  do 
the  liver  structure,  which  is  probably  the  reason  that  phosphorus, 
bacterial  poisons,  snake  poisons,  and  other  poisons  that  destroy 
liver-cells  do  not  ordinarily  produce  the  typical  picture  of  liver 
atrophy.  When  these  poisons  affect  the  liver  more  and  the 
other  tissues  less,  we  approach  the  condition  of  acute  yellow 
atrophy ;  e.  g.,  if  the  dose  of  phosphorus  is  not  so  great  as  to 
kill  the  patient  through  injury  of  other  more  vital  organs,  after 
a  few  days  the  necrosed  liver-cells  undergo  autolysis,  and  if 
enough  liver-cells  have  been  destroyed,  hepatic  insufficiency  may 
cause  death,  with  the  finding  of  an  anatomical  condition  in  the 
liver  that  can  be  properly  designated  as  acute  atrophy.  Hence 
it  is  possible  for  many  poisons  to  cause  this  condition  under 
certain  circumstances,  and  there  seem  to  be  certain  unknown 
poisons  (probably  of  intestinal  origin  2 )  that  are  of  such  a  nature 
that  they  cause  specifically  acute  hepatic  atrophy.  The  above 
hypothesis  seems  to  explain  all  the  known  facts  concerning  this 
disease.  That  phosphorus,  chloroform,  and  some  other  poisons 
lead  particularly  to  fatty  changes  may,  perhaps,  be  due  to  their 
acting  especially  upon  the  oxidizing  enzymes,  leaving  the  auto- 
lytic  enzymes  and  the  lipase  free  to  digest  the  cell  and  to  form 
fat.3  That  it  is  particularly  the  oxidizing  enzymes  that  are 
attacked  is  well  shown  by  the  chemical  findings,  and  also  by 
Loewy's4  observation  that  in  poisoning  with  CNH,  which 
acts  by  impairing  oxidation,  the  alterations  in  proteid  metabo- 
lism are  very  similar  to  those  of  phosphorus  poisoning.5 

1  The  mortality  of  cases  sufficiently  typical  to  be  diagnosed  antemortem  is 
estimated  by  Kondaky  (Koussky  Vratch;  Oct.  28,  1900)  at  97  to  98  per  cent. 
Concerning  the  regenerative  changes  in  the  cases  which  recover,  see  Yamasaki 
(Zeit.  f.  Heilk.,  Path.  Abt,  1903  (24),  248). 

2  See  Carbone,  Kiforma  Med.,  1902  (1),  687  and  698. 

3  Wells,  Jour.  Amer.  Med.  Assoc.,  1906  (46),  341. 

4  Cent.  f.  Physiol.,  1906  (19),  23. 

5  The  hypothesis  suggested  by  Quincke  (NothnagePs  Handbook,  1899,  vol. 
18,  p.  307)  that  possibly  regurgitation  of  pancreatic  juice  up  the  bile-ducts 
might  be  responsible  for  the  degenerative  changes  in  the  liver,  is  contradicted 
by  the  fact  that  the  bile  pressure  is  greater  than  the  pancreatic  juice  pressure, 
and  that  the  bile-ducts  and  peripheral  portions  of  the  lobules  are  least  affected. 
Nor  could  Best  prove  that  trypsin  injected  into  the  liver  by  way  of  the  bile- 
ducts  is  able  to  cause  such  changes.     (See  Wells  and  Bassoe,  loc.  cit.) 


CHEMICAL  CHANGES  OF  ACUTE  YELLOW  ATROPHY  447 
CHEMICAL  CHANGES  OF  ACUTE  YELLOW  ATROPHY 

The  Urine. — Most  striking,  and  long  regarded  as  pathog- 
nomonic,  is  the  presence  of  leucin  and  tyrosin  in  the  urine,  first 
described  by  Frerichs.  While  we  now  know  that  these  and 
other  amino-acids  may  occur  in  the  urine  in  any  conditions 
where  there  is  a  great  breaking  down  of  tissue  within  the  body, 
yet  it  is  true  that  in  no  other  condition  are  they  found  so  abun- 
dantly as  in  acute  hepatic  atrophy  (as  high  as  1.5  gm.  of  tyro- 
sin  per  diem  has  been  found1).  They  are  nearly  constantly 
present  (in  thirteen  out  of  fourteen  cases  studied  by  Biess 2), 
tyrosin  being  usually  the  more  abundant.  Deutero-proteose  is 
also  frequently  (but  not  constantly)  found,  as  further  evidence  of 
abnormal  proteid  splitting.3  Uric  acid  and  other  purins  are 
often  somewhat,  but  not  characteristically,  increased,  probably 
resulting  from  the  nuclear  destruction  in  the  liver.  The  total 
elimination  of  nitrogen  is  increased4  (particularly  if  the  scanty 
intake  is  considered),  and  the  proportion  that  appears  as  urea  is 
decreased,  largely  because  of  the  presence  of  much  ammonia, 
part  of  which,  at  least,  is  eliminated  combined  with  organic 
acids.  Chief  of  these  acids  is  sarcolactic  acid,  but  of  particular 
interest  is  the  appearance  of  oxymandelic  acid, 

— COOH, 

which  is  apparently  derived  from  tyrosin, 

HO/     \CH2— CH(NH2)— COOH, 

by  the  splitting  out  of  the  NH2  group,  the  benzene  nucleus 
failing  to  be  completely  oxidized,  as  is  normally  the  case.  It  is 
evident  from  the  urinary  findings,  therefore,  that  oxidation  is 
decreased,  which  is  presumably  because  of  the  destruction  of  liver 
tissue  with  its  important  oxidizing  functions.  The  reduction  of 
oxidation  can  also  be  shown  experimentally  by  studying  the 
respiratory  exchange,  Welsch 5  having  found  the  oxidation 

1  An  interesting  exception  has  been  reported  by  W.  G.  Smith  (Practitioner, 
1903  (70),  155)  who  found  great  quantities  of  leucin  in  the  urine  of  a  young 
woman  who  was  apparently  not  at  all  ill. 

2  Berl.  klin.  Woch.,  1905  (42),  No.  44  a.,  p.  54. 

3  Salkowski  (Berl.  klin.  Woch.,  1905  (42),  1581)  found  in  the  urine  of  a  case 
of  acute  yellow  atrophy  a  large  quantity  of  nitrogen  in  a  colloidal  but  non- 
proteid  form,  apparently  of  carbohydrate  nature.     Mancini  (Arch,  di  farm, 
sperim.,  1906,  Bd.  v)  also  observed  an  increase  in  the  colloidal  nitrogen  of 
the  urine  in  liver  diseases. 

4  See  Welsch,  Arch.  int.  pharm.  et  The*r.,  1905  (14),  211. 

5  Loc.  cit. 


448  METABOLIC  ABNORMALITIES,  AUTOINTOXICATION 

decreased  by  from  ^  to  £  in  phosphorus  poisoning.  Carbaraates 
do  not  seem  to  be  present  in  recognizable  amounts,  and  sugar 
is  also  absent. 

In  phosphorus  poisoning  the  urinary  findings  are  similar, 
but  with  marked  quantitative  differences.  Tyrosin  cannot 
usually  be  detected,  at  least  by  ordinary  methods,  being  found 
by  Riess  in  but  7  of  36  cases  of  (human)  phosphorus  poison- 
ing, and  in  but  4  of  these  was  it  abundant.  Leucin  is  even 
less  frequently  found.  With  experimental  animals  glycocoll 
and  other  amino-acids  have  been  found l  in  the  urine,  and  they 
could  probably  be  found  in  acute  hepatic  atrophy  if  the  same 
delicate  methods  were  employed.  Wohlgemuth2  has  indeed 
found  glycocoll,  alanin,  and  arginin  in  human  urine  after  phos- 
phorus poisoning.  The  small  quantity  of  amino-acids  in 
phosphorus  poisoning  is  probably  due  to  the  relative  slowness 
of  the  autolytic  changes.  On  the  other  hand,  the  deficiency  of 
oxidation  in  phosphorus  poisoning  is  shown  by  the  abundant 
elimination  of  organic  acids,  Riess  having  obtained  as  high  as 
4  to  6  grams  of  the  zinc  salt  of  paraladic  acid  from  the  urine 
(per  liter)  in  human  cases,  and  its  presence  seems  to  be  con- 
stant. 

The  I4ver. — In  the  liver  may  be  found  an  abundance  of  the 
free  amino-acids  that  have  not  yet  escaped  by  diffusion,  their 
presence  having  been  first  detected  by  Frerichs  microscopically. 
Taylor  3  was  able  to  isolate  from  a  liver  weighing  900  grams 
0.35  gm.  of  leucin  and  0.612  gm.  aspartic  acid,  which  probably 
represent  much  less  than  the  total  amount  present.  Deutero- 
albumose  was  also  found,  but  no  peptone,  arginin,  histidin,  or 
lysin,  and  glycogen  was  also  absent.  In  another  case  that 
appeared  to  be  the  result  of  chloroform  intoxication,  Taylor4 
obtained  4  grams  of  leucin,  2.2  grams  of  tyrosin,  and  2.3  grams 
of  arginin  nitrate.  Wakeman  5  found  that  in  phosphorus  poi- 
soning of  dogs  the  liver  shows  a  diminution  of  the  hexone  bases 
as  a  whole,  the  arginin  being  especially  reduced ;  and  Wohl- 
gemuth6 found  arginin  in  the  urine  in  phosphorus  poisoning. 
The  lecithin  of  the  liver  is  also  decreased  (Heffter7),  and  the 
increase  in  P2O5  observed  in  the  urine  presumably  comes  partly 

1  Abderhalden  and  Barker,  Zeit.  physiol.  Chem.,  1904  (42),  524  ;  Abderhal- 
den  and  Bergell,  ibid.,  1903  (39),  464. 
2 Zeit.  physiol.  Chem.,  1905  (44),  74. 

3  Zeit.  physiol.  Chem.,  1902  (34),  580  ;  Jour.  Med.  Eesearch,  1902  (8),  424. 
4Univ.  of  Calif.  Publications  (Pathol.),  1904  (1),  43. 

5  Jour.  Exper.  Med.,  1905  (7),  292. 

6  Zeit.  physiol.  Chem.,  1905  (44),  74. 

7  Arch.  exp.  Path.  u.  Pharm.,  1891  (28),  97. 


CHEMICAL  CHANGES  OF  ACUTE  YELLOW  ATROPHY  449 


from  this  source.  Beebe *  found  the  pentose  of  the  liver  not 
greatly  altered  from  the  normal  relations.  The  typical  idio- 
pathic  atrophied  liver  shows  little  or  no  increase  in  fat,  either 
chemically  or  microscopically,  whereas  there  is  considerable 
replacement  of  the  lost  liver  substance  by  water,  as  shown  in 
the  following  table 2 : 


Water. 

Fat. 

Fat-free 
dried 
substance. 

76.1 

87.6 
76.9 
80.5 
60.0 
64.0 

3.0 
8.7 
7.6 
4.2 
29.8 
25.0 

20.9 
9.7 
15.5 
15.3 
10.0 
11.0 

Acute  atrophy  (Perls) 

"            "        (Perls)                      .    .    . 

"            "        (v   Starck) 

Phosphorus-poisoning  (v.  Starck)  .    .    . 
Fatty  degeneration  (v.  Starck)    .... 

Similar  results  have  been  obtained  frequently  by  other  observers, 
Taylor  estimating  that  in  his  case  about  three-fourths  of  the 
liver  parenchyma  had  disappeared.  The  yellow  color  of  the 
liver  tissue  characteristic  of  this  condition  seems  to  be  due  to 
bilirubin  rather  than  to  fat,  because  as  soon  as  the  tissues  are 
put  into  oxidizing  agents  (e.  g.,  dichromate  hardening  fluids) 
they  turn  grass-green  from  the  oxidation  of  the  bilirubin  into 
biliverdin. 

Jacoby 3  found  that  the  livers  from  phosphorus-poisoned  dogs 
underwent  autolysis  with  greater  rapidity  than  normal  livers, 
which  was  attributed  to  increased  activity  or  amount  of  the 
autolytic  enzymes,  although  addition  of  phosphorus  to  a  solu- 
tion containing  liver  ferments  was  not  found  to  increase  their 
activity.  The  aldehydase  was  not  found  decreased,  and  tyro- 
sinase  could  not  be  demonstrated. 

The  Blood. — In  the  blood  marked  changes  are  found,  one 
of  the  most  prominent,  besides  the  icterus,  being  the  decreased 
coagulability  of  the  blood.  This  seems  due  to  a  loss  of  fibrin- 
ogen,  which,  with  the  globulin,  is  greatly  decreased,  the  albu- 
min remaining  less  altered.4  The  fibrin-ferment  also  seems  to 
be  decreased.  These  changes  may  be  due  to  direct  autolysis  of 
the  blood  constituents  (Jacoby  having  found  that  thrombi 
become  rapidly  dissolved  in  phosphorus-poisoning)  or  to  the 
changes  in  the  liver.  The  icterus  depends  apparently  upon 

JAmer.  Jour,  of  Physiol.,  1905  (14),  237. 

2  From  Quincke,  Nothnagel's  System,  1899,  vol.  18,  p.  297. 

3Zeit.  physiol.  Chem.,  1900  (30),  174. 

*  Jacoby,  loc.  cit. ;  see  also  Doyon,  Compt.  Rend.  Soc.  BioL,  1905  (58),  493. 


450  METABOLIC  ABNORMALITIES,  A  UTOINTOXICATION 

lesions  of  the  finest  bile  capillaries,1  although  there  is  also  some 
increase  in  hemolysis,  and  a  decrease  in  the  total  blood  and  all 
its  elements  (Welsch 2 ) ;  and  both  bile  salts  and  pigments 
appear  in  the  urine.  Neuberg  and  Richter 3  have  analyzed  the 
blood  drawn  during  life  from  a  patient  with  acute  hepatic 
atrophy,  and  isolated  from  355  c.c.  of  blood  0.787  gm.  tyrosin, 
1.102  gm.  leucin,  and  0.240  gm.  of  lysin  ;  they  estimated  the 
amount  of  free  amino-acids  in  the  entire  blood  to  be  about  30 
grams.  This  amount  is  so  large  that  they  question  the  possi- 
bility of  it  all  arising  from  the  degenerated  liver  tissue ;  but 
more  analyses  are  necessary  before  conclusions  on  this  point  can 
be  drawn.4 

Origin  of  the  Amino-acids. — The  earliest  conception  of 
the  source  of  the  leucin  and  tyrosin  found  in  the  urine  was  that 
it  came  from  the  products  of  tryptic  digestion  absorbed  from 
the  intestinal  tract,  which  the  liver  could  not  convert  into  urea 
because  of  its  damaged  condition.  On  the  demonstration  by 
Jacoby 5  that  these  same  bodies  were  present  in  the  livers  of 
phosphorus-poisoned  animals  because  of  autolysis,  it  became 
probable  that  the  leucin  and  tyrosin  found  in  the  urine  were 
formed  from  the  degenerated  liver-cells  rather  than  in  the  intes- 
tine, which  view  has  become  generally  accepted.  In  support  of 
this  view  are  also  the  observations  which  indicate  that  the 
amino-acids  formed  in  the  intestine  are  resynthesized  or  other- 
wise altered  in  passing  through  the  intestinal  wall.  Neuberg 
and  Richter  have,  however,  suggested  that  the  urinary  amino- 
acids  are,  at  least  in  part,  derived  from  the  intestinal  contents, 
assuming  that  they  may  pass  unaltered  through  the  intestinal 
wall  because  of  pathological  alterations  in  its  structure.  It 
seems  most  probable  that  the  urinary  amino-acids  are  derived 
partly  (and  perhaps  chiefly)  from  the  autolysis  of  the  liver,  and 
partly  from  amino-acids  produced  both  in  the  intestine  and 
within  the  body  during  tissue  metabolism,  and  which  the  liver 
cannot  transform  into  urea  as  it  normally  does. 

1  Lang  (Zeit.  exp.  Path.,  1906,  Bd.  3,  July)  found  fibrinogen  in  the  bile  of 
a  dog  poisoned  with  phosphorus,  which  may  account  for  the  occlusion  of  the 
bile  vessels  and  the  resulting  jaundice. 

2  Arch.  int.  Pharm.  et  Ther.,  1905  (14),  197. 
3Deut.  med.  Woch.,  1904  (30),  499. 

4v.  Bergmann  (Hofmeister's  Beit.,  1904  (6),  40)  was  able  to  isolate  2.3 
grams  of  amino-acids  combined  with  the  chloride  of  naphthalene  sulphonie 
acid,  from  270  c.c.  of  blood  in  a  case  of  acute  yellow  atrophy. 

5  Zeit.  physiol.  Chem.,  1900  (30),  174. 


ACID  INTOXICATION  451 


ACID  INTOXICATION1 

If  a  rabbit  is  given  in  repeated  small  doses  by  mouth  con- 
siderable quantities  of  inorganic  acids,  such  as  hydrochloric  or 
phosphoric  acids,  which  it  cannot  destroy  by  oxidation,  it  soon 
becomes  extremely  sick.  The  manifestations  are  characteristic 
— unsteadiness  of  motion  and  stupor  being  followed  by  coma, 
in  which  the  striking  feature  is  the  excessively  active  respiration, 
as  if  the  animal  were  being  asphyxiated  (the  so-called  "  air 
hunger  "),  while  at  the  same  time  there  is  no  cyanosis  and  the 
blood  is  bright  red,  containing  much  less  CO2  than  normal, 
while  the  amount  of  oxygen  remains  quite  normal.  The 
explanation  of  this  interesting  condition  is  as  follows  :  Nor- 
mally the  blood  carries  the  CO2  away  from  the  tissues  to  the 
lungs  in  combination  with  the  inorganic  alkalies  of  the  blood, 
of  which  sodium  is  by  far  the  most  abundant.  This  combina- 
tion is  the  bicarbonate  of  sodium  (or  other  base),  which  in  the 
lungs  is  decomposed  into  the  carbonate,  the  CO2  escaping  into 
the  alveolar  air,  according  to  this  equation  : 

2NaHCO3      =    Na2CO3     +      H2O     +     CO2. 

The  carbonate  thus  formed  goes  back  to  the  tissues  to  again 
combine  with  more  CO2  and  form  bicarbonate.  If  acids  are 
introduced  into  the  blood  they  combine  with  the  alkalies  there, 
forming  neutral  salts  which  are  eliminated  in  the  urine,  and  in 
this  way  the  amount  of  alkali  in  the  blood  is  reduced,  with  a  con- 
sequent reduction  in  the  capacity  of  the  blood  to  carry  CO2 
away  from  the  tissues  ;  the  amount  of  CO2  in  the  blood  sinking 
from  the  normal  24  per  cent,  to  as  low  as  2.5  and  3  per  cent. 
(Walter).  Consequently,  in  acid  poisoning  the  CO2  produced 
in  metabolism  accumulates  in  the  tissues  where  it  is  formed,  and 
blocks  the  processes  of  oxidation,  so  that  the  animal  suffers 
from  asphyxia  exactly  as  if  it  were  deprived  of  air.  In  other 
words,  the  lack  of  alkalies  in  the  blood  in  acid  intoxication 
checks  the  "  internal  respiration,"  as  intracellular  gas  exchange 
is  called,  by  preventing  the  removal  of  CO2  from  the  cells. 

If  the  urine  of  such  an  animal  is  analyzed,  it  is  found  to 
contain  increased  quantities  of  the  four  chief  inorganic  bases, 
Na,  K,  Ca,  and  Mg  (the  last  two  apparently  being  derived  from 
the  bones),  but  in  addition  to  these  it  is  found  that  the  amount 
of  ammonia  in  the  urine  is  decidedly  increased.  If  instead  of 

1  General  literature  will  be  found  in  Waldvogel's  "  Die  Acetonkorper," 
Stuttgart,  1903  ;  v.  Noorden's  "Die  Zuckerkrankheit  und  ihre  Behandlung"  * 
in  Krehl's  "  Pathologische  Physiol.,"  pp.  397-406  ;  and  in  the  articles  cited  in 
the  text. 


452  METABOLIC  ABNORMALITIES,  AUTOINTOXICATION 

a  rabbit  a  carnivorous  animal,  such  as  a  dog,  is  given  acids,  it 
will  be  found  relatively  insusceptible,  so  that  great  quantities 
can  be  given  without  causing  acid  intoxication.  Examination 
of  the  urine  of  such  a  dog  will  show  that  the  elimination  of 
ammonia  is  increased  much  more  than  it  is  in  the  herbivora, 
while  the  inorganic  alkalies  are  relatively  increased  but  little. 
From  this  it  is  deduced  that  in  acid  intoxication  part  of  the 
nitrogen  that  normally  goes  to  form  urea  becomes,  while  in 
the  antecedent  form  of  ammonia,  combined  with  part  of  the 
acid  that  has  entered  the  blood.  In  this  way  much  of  the 
neutralization  of  the  acids  is  accomplished  by  ammonia,  and 
the  inorganic  alkalies  of  the  blood  are  spared.  As  in  carnivora 
the  amount  of  proteid  metabolism  is  much  greater  and  more 
rapid  than  in  herbivora,  the  ammonia  available  for  neutraliza- 
tion of  acids  is  much  greater  than  in  the  latter,  and  hence  the 
relative  lack  of  susceptibility  of  carnivora  to  acid  poisoning.1 
According  to  Landau,2  the  proteids  of  the  blood  also  combine 
much  of  the  acid — probably  one-half  of  it  and  perhaps  more. 

DIABETIC  COMA  3 

In  man,  poisoning  with  inorganic  poisons,  as  in  the  experi- 
ments cited  above,  is  a  rare  occurrence,  but  not  infrequently 
acid  intoxication  results  from  the  presence  of  undue  quantities 
of  organic  acids  produced  in  metabolism.  The  most  striking 
example  of  this  is  the  coma  of  diabetes,  in  which  the  asphyxia 
without  cyanosis,  dependent  upon  failure  of  the  blood  to  carry 
CO2,  is  strikingly  similar  to  that  observed  in  experimental  ani- 
mals poisoned  with  acids.  In  diabetic  coma  the  acid  intoxica- 
tion is  due  chiefly  to  the  accumulation  in  the  blood  of  large 
quantities  of  ft-oxybutyric  add.  Associated  with  it,  in  smaller 
quantities,  are  usually  found  diacetic  (aceto-acetic)  acid  and 
acetone,  which  are  chemically  so  closely  related  that  it  is  gener- 
ally considered  that  they  are  derived  from  the  oxybutyric  acid, 
as  follows: 

/9-oxybutyric  acid  is — 

CH3  —  CHOH  —  CH2  —  COOH, 

and  by  oxidation  this  readily  forms — 

CH3  —  CO  —  CH2  —  COOH, 

lrThis  has  been  nicely  shown  by  Eppinger  (Wien.  klin.  Woch.,  1906  (19), 
111),  who  found  that  administration  of  considerable  quantities  of  ammo-acids 
(glycocoll,  alanin,  aspartic  acid)  to  rabbits  greatly  increased  their  resistance  to 
acid  intoxication,  presumably  by  yielding  ammonia  through  the  normal  steps 
of  proteid  metabolism. 

2  Arch.  exp.  Path.  u.  Pharm.,  1900  (52),  271. 

3  See  also  v.  Noorden's  "  Diabetes  Mellitus,  "  1905,  New  York. 


ACID  INTOXICATION,  DIABETIC  COMA  453 

which  is  diacetic  acid  (being  two  molecules  of  acetic  acid 
united  to  each  other,  as  follows) : 

CH3  —  CO  —  |  OH  —  Hj— H2C  —  COOH. 

Diacetic  acid  is,  in  turn,  readily  deprived  of  its  COOH  group 
through  oxidation,  forming  acetone, 

CH3  — CO  — CH3. 

All  these  reactions  are  readily  accomplished  in  the  labora- 
tory, and  we  have  good  reason  for  believing  that  they  normally 
occur  in  the  same  way  in  the  animal  body.  (Because  of  their 
chemical  relation  these  substances  are  often  referred  to  collect- 
ively as  the  "  acetone  bodies  ").  As  long  as  a  diabetic  is  main- 
taining a  good  metabolic  equilibrium  the  urine  is  free  from  both 
acids,  although  small  amounts  of  acetone  (traces  of  which — 
under  0.02  grn.  per  day — occur  in  normal  urine l)  may  be  present ; 
but  when  wasting  sets  in  the  two  acids  appear,  combined  largely 
with  ammonia,  but  partly  with  mineral  bases.  Normally  but 
2  to  5  per  cent,  of  the  nitrogen  of  the  urine  is  in  the  form  of 
ammonia,  but  in  diabetic  acidosis  the  proportion  may  reach 
from  10  to  25  per  cent.,  the  amount  of  urea  being  correspond- 
ingly reduced.2 

The  presence  of  large  quantities  of  these  acids  in  the  urine 
presages  coma,  during  which  the  amount  of  oxybutyric  acid 
often  reaches  15-20  grams  per  day,  and  has  been  known  to 
reach  150  grams  (Kiilz  claimed  to  have  found  226  grams). 
Diacetic  acid  appears  in  relatively  small  amounts,  rarely  exceed- 
ing 10  per  cent,  of  the  total  organic  acids  of  the  urine.  When 
oxybutyric  acid  is  present  the  other  two  substances  are  always 
present,3  but  the  converse  is  not  true.  In  the  development  of 
acetonuria,  acetone  is  the  first  of  the  three  bodies  to  appear ; 
when  0.4  to  0.5  gm.  of  acetone  is  present  in  the  day's  urine 
diacetic  acid  may  be  found,  but  oxybutyric  acid  does  not  usually 
appear  until  the  amount  of  acetone  exceeds  1  gram.  After 
this  the  chief  increase  is  in  the  oxybutyric  acid,  which  often 
reaches  30  to  80  grams,  whereas  the  diacetic  acid  and  acetone 
together  rarely  exceed  7  to  8  grams  (v.  Noorden).  In  the 
internal  organs  the  acetone  bodies  may  also  be  detected.  Geel- 
muyden  4  found  that  the  organs  of  diabetics  contain  consider- 

1  Concerning  normal  occurrence  of  acetone  in  blood  and  tissues,  see  Halpern 
and  Landau,  Zeit.  exp.  Path.  u.  Ther.,  July,  1906,  Bd.  3. 

2  According  to  Edie  and  Whitley  (Biochemical  Jour.,  1906  (1),  11),  ad- 
ministration of  excessive  amounts  of  alkali  causes,  conversely,  elimination  of 
increased  amounts  of  organic  acids. 

3  See  Pavy,  Lancet,  1902  (U).  64  el.  scq.  (general  review). 
*Zeit.  physiol.  Chem.,  1904  (41),  128. 


454  METABOLIC  ABNORMALITIES,  AUTOINTOXICATION 

able  acetone,  the  liver  less  than  the  other  viscera  ;  the  blood 
contains  less  acetone  than  the  urine  of  the  same  patient. 

Relation  of  Acidosis  to  Diabetic  Coma. — There 
seems  to  be  little  room  for  doubt  but  that  the  typical  diabetic 
coma  with  "air  hunger"  depends  upon  an  excess  of  these 
substances  in  the  blood — i.  e.,  is  an  acid  intoxication — for  the 
following  reasons  :  (1)  The  coma  appears  when  the  amount  of 
organic  acids  in  the  urine  is  highest,  and  is  absent  when  there  is 
little  or  none  of  them  in  the  urine.  (2)  Because  of  the  identity 
of  the  symptoms  with  those  of  experimental  acid  intoxication. 
(3)  Because  of  the  repeated  demonstration  of  a  reduced  amount 
of  alkali  in  the  blood,  as  determined  by  titration,1  and  a  great 
reduction  of  the  amount  of  CO2  carried  in  the  venous  blood 
(from  the  normal  36  per  cent,  it  may  be  reduced  to  3.3  per 
cent.— Minkowski).  (4)  The  marked  improvement  that  often 
results  from  the  administration  of  alkalies  (usually  sodium  bi- 
carbonate). Associated  with  this  improvement  is  an  elimination 
of  greatly  increased  amounts  of  organic  acids,  indicating  their 
previous  retention  in  the  body  because  of  lack  of  alkali  with 
which  they  could  combine  (or  their  liberation  from  combination 
with  proteids — Landau). 

/9-oxybutyric  and  diacetic  acid,  according  to  many  authorities, 
seem  to  have  no  specific  poisonous  effects,2  but  act  simply  as 
acids  in  the  blood.3  Acetone  does  not  have  this  effect,  not 
being  an  acid,  and  seems  not  to  be  toxic  to  any  considerable 
degree ;  doses  of  4  grams  per  kilo  cause  effects  similar  to  ethyl 
alcohol  in  dogs,  8  grams  per  kilo  being  fatal,  which  corresponds 
with  a  dose  of  500  grams  for  an  adult  man.  Of  course  a 
diabetic  suffers  from  the  effects  of  other  poisons  than  these 
acids,  and  often  the  coma  cannot  be  relieved  by  alkaline  treat- 
ment, and  seems  not  to  be  due  to  the  acids  alone.  But,  in  the 
majority  of  cases,  the  acids  seem  to  be  the  chief  factor,  as 
shown  by  the  marked  effect  of  alkaline  treatment. 

1  The  actual  alkalinity  of  normal  blood,  which  means  the  number  of  free 
OH  ions,  is  but  little  greater  than  that  of  distilled  water,  and  the  condition  is 
quite  the  same  in  diabetic  acidosis  (Benedikt  and  T6r6k,  cit.  in  Folia  Hemato- 
logia,  1905  (2),  454). 

2  Some,  however,  attribute  to  oxybutyric  acid  a  considerable  toxicity  inde- 
pendent of  its  acidity. 

3  The  view  advanced  by  Stemberg  (Zeit.  f.  klin.  Med.,  1899  (38),  65)  that 
an  antecedent  of  oxybutyric  acid,  namely,  ammo-butyric  acid,  is  responsible  for 
the  intoxication,  does  not  seem  to  have   been  generally  accepted,  although 
Grube  (Arch.  f.  exp.  Pathol.,  1900  (44),  349)  found  that  o-amino-butyric  acid 
is  toxic  and  produces  symptoms  similar  to  those  of  diabetic  coma.      Magnus- 
Levy  questions  the  possibility  of  sufficient  amino-butyric  acid  being  present  to 
account  for  the  great   amount  of  acid  eliminated  in  the   urine  (Arch.  exp. 
Path.  u.  Pharm.,  1901  (45),  389). 


ACID  INTOXICATION  455 

Origin  of  the  Acetone  Bodies.  —  As  yet  we  are  uncer- 
tain as  to  the  origin  of  these  acetone  bodies.  Their  close 
chemical  relation  with  one  another  makes  it  seem  probable  that 
they  have  a  common  source,  and  it  is  also  probable  that  they  are 
not  abnormal  products  of  metabolism,  produced  only  in  patients 
with  acid  intoxication,  but  that  they  are  formed  normally  in 
metabolism,  and  accumulate  when  they  cannot  be  destroyed  as 
they  normally  are,  through  oxidation.  Acid  intoxication,  there- 
fore, is  dependent  upon  a  failure  of  complete  oxidation  of 
organic  acids  produced  in  metabolism.  But  whether  the 
acids  are  formed  from  fats,  or  from  carbohydrates,  or  from 
proteids,  or  from  all  three,  has  not  been  conclusively  deter- 
mined. Their  chemical  nature  is  such  that  they  might  readily 
be  produced  from  any  or  all  of  the  three  classes  of  food- 
stuffs. 

They  might  be  derived  from  carbohydrates,  as  is  the  closely 
related  lactic  acid,  but  it  is  generally  believed  that  this  is  not  the 
usual  source,  particularly  because  administration  of  a  proper 
amount  of  carbohydrates  under  certain  conditions  may  cause 
the  acids  to  disappear  from  the  urine,1  and  because  the  acids 
may  be  eliminated  in  large  quantities  while  the  patient  is  on  a 
diet  almost  free  from  carbohydrates. 

They  might  readily  be  formed  from  proteids  through  splitting 
out  of  the  NH2  group  from  the  amino-acids,  just  as  in  acute 
yellow  atrophy  we  may  find  in  the  urine  oxymandelic  acid, 

HO/~~\CHOH—  COOH, 

derived  from  tyrosin, 

2  —  CHNH2  —  COOH, 


by  removal  of  the  nitrogen-containing  radical,  with  subsequent 
failure  of  normal  oxidation  of  the  non-nitrogenous  residue. 
Indeed  the  amino-acids  are  generally  considered  as  the  chief 
source  of  the  acetone  bodies,2  particularly  because  whenever 
there  is  considerable  pathological  breaking-down  of  proteids 
these  bodies,  especially  acetone,  may  appear  in  the  urine  ;  e.  g.,  in 
patients  with  retained  placenta  or  dead  fetus,  during  absorption 

1  See  Satta,  Hofmeister's  Beitr.,  1905  (6),  376. 

2  Embden  and  his  associates  have  recently  (Hofmeister's    Beitr.,  1906  (8), 
121)  demonstrated  that  the  liver  can  form  acetone  from  many  substances  per- 
fused through  it  in  the  blood,  including  not  only  amino-acids  of  the  fatty  acid 
series,  but  also  from  the  aromatic  radicals  of  the  proteid  molecule. 


456  METABOLIC  ABNORMALITIES,   AUTOINTOXICATION 

of  exudates,  in  carcinoma,  and  in  starvation  or  other  conditions 
with  great  wasting  of  the  tissues.1 

On  the  other  hand,  the  amount  of  acids  sometimes  found  in 
the  urine  seems  to  be  greater  than  can  be  explained  by  the 
proteid  destruction  that  occurs  (Magnus-Levy  2),  and  hence  it 
has  been  thought  that  acetone  bodies  may  be  derived  from  the 
fats.  /3-oxybutyric  acid  can  be  readily  produced  from  fatty 
acids,  especially,  of  course,  from  butyric  acid,  and  Schwarz 
observed  an  increase  in  the  acetone  excretion  in  a  diabetic  given 
large  quantities  of  butter.  Other  higher  fatty  acids  were  also 
found  to  cause  increased  acetone  excretion.  Joslin,3  however, 
found  that  butyric  acid  does  not  increase  the  acetonuria  of  a 
healthy,  fasting  individual,  nor  do  neutral  fats ;  oleic  acid  and 
sodium  palmitate,  on  the  other  hand,  caused  a  marked  aceton- 
uria. It  is  furthermore  possible,  but  this  is  purely  hypothetical, 
that  the  acetone  bodies  may  be  synthesized  from  other  simpler 
substances. 

Sarcolactic  acid  appears  in  the  urine,  particularly  when  the 
liver  is  badly  incapacitated,  and,  therefore,  is  rarely  found  in 
diabetes,  but  is  a  prominent  finding  in  phosphorus-poisoning, 
acute  yellow  atrophy,  and  in  puerperal  eclampsia.  (See  preceding 
sections  of  this  chapter.)  The  amount  is  never  sufficient  to 
cause  an  acid  intoxication  by  abstraction  of  alkali  from  the 
blood,  nor  does  it  seem  to  possess  sufficient  toxicity  to  cause  all 
of  the  manifestations  of  puerperal  eclampsia,  as  has  been  sug- 
gested. It  is  normally  present  in  the  muscles,  being  produced 
in  increased  amounts  during  exercise,  and  therefore  it  may 
appear  in  the  urine  after  violent  and  protracted  muscular 
exertion  ;  apparently  this  acid  is  destroyed  in  the  liver  through 
oxidation,  and  therefore  appears  in  the  urine  when  the  liver  is 
disorganized,  but  there  is  also  much  reason  for  believing  that 
under  these  conditions  the  sarcolactic  acid  found  in  the  urine 
comes  from  the  disintegrating  cells  themselves.4  Sarcolactic 
acid,  which  is  dextrorotary,  must  be  distinguished  from  its 
optical  isomer,  the  inactive  lactic  acid  that  is  produced  by 
fermentation.  When  this  fermentation  lactic  acid  is  formed  in 


1  Kesume  by  Mauban,  These  de  Paris,  1905. 

2  Arch.  exp.  Path.  u.  Pharm.,  1899  (42),  149. 

3  Jour.  Med.  Research,  1904  (12),  433. 

4  Mandel,    however,   considers   that    sarcolactic    acid  comes    from  carbo- 
hydrates, since  phosphorus-poisoning  does  not  cause  the  appearance  of  lactic 
acid  in  the  urine  of  dogs  with  experimental  (phlorhizin)  diabetes,  and  when 
produced  by  phosphorus-poisoning  the  administration  of  phlorhizin  checks  it 
(Amer.  Jour.  Physiol.,  1905  (13),  p.  xvi) ;    also  see  Mandel  and  Lusk,  ibid., 
1906  (16),  129. 


ACID  INTOXICATION  457 

the  stomach  and  enters  the  blood,  it  ordinarily,  like  other  ingested 
organic  acids,  is  combined  by  the  blood  alkalies  and  oxidized  to 
carbonates.  It  is  doubtful  if  it  ever  enters  the  urine.1 


ACID  INTOXICATION  IN  CONDITIONS  OTHER  THAN  DIABETES 

Not  infrequently  acetone  and  diacetic  acid,  less  often  oxy- 
butyric  acid,  are  found  in  the  urine  of  patients  suffering  from 
the  most  diverse  diseases.  It  is  customary  to  refer  to  this 
condition  as  "acetonemia  "  or  "  acetonuria"  and  to  ascribe  many 
of  the  observed  symptoms  to  "acid  intoxication."  The  acetone 
bodies,  however,  being  without  specific  toxic  effects,  can  probably 
cause  only  such  symptoms  as  described  in  discussing  diabetic 
coma,  and  these  are  due  to  their  reducing  the  carrying  power 
of  the  blood  for  CO2.  Therefore,  the  intoxication  in  these 
cases  is  probably  not  due  to  the  acids,  but,  on  the  contrary,  the 
presence  of  the  acetone  bodies  is  due  more  often  to  the  effects 
upon  the  liver  of  toxic  substances  of  diverse  origins  and  natures. 
In  no  other  condition  do  the  amounts  of  organic  acids  in  the 
urine  approximate  the  amounts  found  in  diabetic  coma. 

Anesthesia. — Most  prominent  of  these  so-called  acid 
intoxications  is  that  following  a  few  days  after  anesthesia, 
particularly  with  chloroform,  and  fully  discussed  by  Bevan  and 
Favill.2  As  shown  first  by  Greven  (1895),  and  more  recently 
especially  by  Brewer  and  by  Helen  Baldwin,3  acetone  is  nearly 
always  present  in  the  urine  during  the  first  twenty-four  hours 
after  administration  of  either  chloroform  or  ether,  and  occasion- 
ally diacetic  acid  appears  on  the  second  or  third  day  after  ;  but 
ordinarily  there  is  no  increase  in  organic  acids  in  the  urine.  It 
does  not  seem  probable  that  the  symptoms  observed  in  typical 
cases  of  delayed  chloroform-poisoning  are  due  chiefly,  if  at  all, 
to  acid  intoxication  per  se,  but  rather  are  the  result  of  extensive 
injury  to  the  parenchymatous  organs,  particularly  the  liver,  by 
the  chloroform,  which  causes  a  condition  resembling  acute 
yellow  atrophy  or  phosphorus-poisoning.4 

Cachectic  Acetonuria. — Acetone  and  diacetic  acid,  but 
less  abundantly  the  oxybutyric  acid,  are  found  in  the  urine  in 
many  conditions  associated  with  wasting,  among  which  may  be 
especially  mentioned : 

1  The  theory  of  Boix  that  cirrhosis  of  the  liver  may  be  produced  by  butyric 
acid  formed  in  gastric  fermentation  could  not  be  corroborated  by  Joannovics, 
Arch.  int.  Pharmacodyn.,  1905  (15),  241. 

2  Journal  Amer.  Med.  Assoc.,  1905  (45),  691. 

3  Jour,  of  Biol.  Chem.,  1906  (1),  239. 

4  Wells,  Jour.  Amer.  Med.  Assoc.,  1906  (46),  341. 


458  METABOLIC  ABNORMALITIES,  AUTOINTOXICATION 

Infantile  marasmus,1  in  which  increased  ammonia  is  found 
in  the  urine,  and  sometimes  symptoms  resembling  acid  intoxica- 
tions occur.  Normally  the  urine  of  suckling  infants  contains 
1-4  mg.  per  day  of  acetone  bodies,  which  may  be  increased  to 
15-35  mg.  by  simple  hunger.  In  fact,  "acidosis"  seems  to 
occur  particularly  frequently  in  infants  from  relatively  slight 
causes,  such  as  gastro-enteritis  and  other  infectious  conditions. 
This  is  perhaps  due  to  a  lower  oxidizing  power  on  the  part  of  the 
infantile  organism  (Pfaundler 2 ),  since  the  proportion  of  nitrogen 
in  the  urine  of  infants  in  forms  other  than  urea,  is  higher  than 
in  adults.  Even  an  unusually  fatty  diet  may  cause  acetonuria 
in  infants. 

Cancerous  cachexia,  in  which  a  "  cancer  coma  "  occasionally 
occurs  that  is  strikingly  like  that  of  diabetic  coma. 

Retention  of  placenta  or  fetus,  acetonuria  being  considered  of 
diagnostic  value  in  determining  the  death  of  the  fetus  in  utero? 

Pernicious  vomiting  of  pregnancy  is  often  associated  with 
acetonuria,4  which  in  some  cases  is  probably  dependent  upon 
starvation  and  proteid  wasting,5  but  in  other  cases  is  probably  due 
to  liver  alterations  resembling  those  of  puerperal  eclampsia  or 
acute  yellow  atrophy.6  Williams7  considers  that  this  condi- 
tion may  result  from  three  varieties  of  etiological  factors, 
namely — reflex,  neurotic,  and  toxemic.  Only  in  the  last  form, 
which  is  associated  with  marked  degenerative  changes  in  the 
liver,  are  there  striking  metabolic  changes.  These  are  indicated 
by  a  marked  increase  in  the  ammonia  nitrogen  of  the  urine, 
which  he  has  observed  to  form  as  much  as  46  per  cent,  of  the 
total  nitrogen.  Starvation  seldom  causes  a  rise  in  the  ammonia 
quotient  above  10—15  per  cent.,  and  Williams  considers  that 
an  ammonia  quotient  of  over  16  per  cent,  is  an  indication  for 
the  interruption  of  pregnancy,  and  even  then  the  prognosis  is 
dubious. 

In  febrile  diseases,  especially  in  children,  acetonuria  is 
often  observed,  apparently  depending  on  wasting  of  the  tissue 
proteids. 

In  uremia,  as  previously  mentioned,  organic  acids  may  ap- 
pear in  the  urine,  but  apparently  as  a  result,  and  not  as  the 
cause,  of  the  uremia  (Orlowski). 

1  See  Meyer  and  Langstein,  Jahrb.  f.  Kinderheilk.,  1906  (63),  30. 

2  Jahrb.  f.  Kinderheilk.,  1901  (54),  247. 

8  See  Frommer,  Berl.  klin.  Woch.,  1905  (42),  1008. 

*  Baldwin,  Amer.  Jour.  Med.  ScL,  1905  (130),  649. 

5  Wolf,  New  York  Med.  Jour.,  1906  (83),  813. 

6Ewing,  Amer.  Jour,  of  Obstet,  1905  (51),  145. 

7  Johns  Hopkins  Hosp.  Bull.,  1906  (17),  71 ;  full  bibliography. 


FATIGUE  459 

Mauban l  distinguishes  the  following  groups  of  conditions 
causing  acetonuria :  Physiological  acetonuria,  diabetes,  febrile 
diseases,  carcinoma,  resorption  of  tissues  and  exudates,  gastro- 
enteritis, nervous  diseases,  general  anesthesia,  and  inanition. 

As  mentioned  in  discussing  these  diseases,  lactic  acid  has 
been  found  in  the  urine  in  osteomalacia  and  in  rickets,  but  the 
attempts  to  explain  these  diseases  as  due  to  solution  of  the  bone 
salts  by  the  organic  acids  have  not  met  with  success.  (See  "  Cal- 
cification/' Chap.  xv).  In  rheumatism  lactic  acid  is  said  to  have 
been  found  in  the  urine  and  sweat,  but  these  results  have  not 
been  verified,  particularly  as  to  the  sweat,  and  the  once  promi- 
nent idea  that  rheumatism  is  due  to  an  acid  intoxication  seems 
to  have  been  given  up.2  In  rheumatoid  arthritis,  as  shown  by 
Herter  and  by  Baldwin,3  there  is  an  excessive  elimination  of  or- 
ganic acids  of  undetermined  nature  in  the  urine. 

FATIGUE 

The  symptoms  of  fatigue,  whether  general  or  local,  seem  to  be 
due  to  an  intoxication  with  the  products  of  the  excessive  meta- 
bolic activity,  and  part  of  the  symptoms,  at  least,  seem  to  be  due 
to  acid  intoxication.  Among  the  metabolic  products  of  muscular 
activity  are  known  to  be  creatin,  creatinin,  sarcolactic  acid,  and 
carbon  dioxide.  The  amount  of  acid  developed  in  an  active 
muscle  is  quite  considerable,  and  when  the  activity  is  violent  or 
prolonged  the  sarcolactic  acid  accumulates,  being  formed  faster 
than  it  can  be  removed.  Part  of  the  acidity  of  the  muscle  is  due, 
however,  not  to  the  sarcolactic  acid  itself,  but  to  monopotassium 
phosphate  (KH2PO4),  which  is  formed  by  the  action  of  the 
sarcolactic  acid  upon  the  dipotassium  phosphate  present  in  the 
blood  and  muscle.  The  effect  of  these  various  substances  upon 
muscular  fatigue  has  been  studied  experimentally,  and  while  the 
creatin  seems  not  to  be  a  "  fatigue  substance,"  sarcolactic  acid, 
monopotassium  phosphate,  potassium  sarcolactate,  and  carbon 
dioxide  all  cause  muscle  tissue  to  react  to  stimuli  in  the  same 
way  that  a  fatigued  muscle  does  (Lee 4). 

It  is  quite  probable  that  the  muscular  weakness  of  diabetics, 
and  the  exhaustion  associated  with  many  conditions  in  which 
organic  acids  appear  in  the  urine  in  abnormal  quantities,  depend, 

1  These  de  Paris,  1905. 

2  See  Garrod,  Treatise  on  Rheumatism,  1890.     Walker  and  Ryffel  (Brit. 
Med.  Jour.,  1903  (ii),  659,  report  finding  formic  acid  in  the  urine  in  acute 
rheumatism. 

3  Amer.  Jour.  Med.  Sci.,  1904  (128),  1038. 

4  Jour.  Amer.  Med.  Assoc.,  1906  (46),  1491 ;  where  is  given  a  complete  re- 
view of  the  subject  of  fatigue,  with  the  literature. 


460  METABOLIC  ABNORMALITIES,  AUTOINTOXICATION 

at  least  in  part,  upon  the  effect  of  these  acids  upon  the  muscle 
tissue,  for  Lee  found  that  /9-oxybutyric  acid  causes  the  same 
fatigue  reaction  in  muscles  as  does  sarcolactic  acid.  Further- 
more, sarcolactic  acid  itself  often  appears  in  the  urine  in  these 
conditions.  It  may  be  added  that  in  fatigued  animals  the 
alkalinity  of  the  blood  (by  titration)  has  been  found  decreased 
(Geppert  and  Zuntz),  and  the  proportion  of  the  urinary  nitrogen 
that  appears  in  other  combinations  than  urea  is  increased 
(Poehl  !). 

The  "  Toxins "  of  Fatigue. — In  extreme  exhaustion 
the  evidences  of  a  general  intoxication  often  become  severe,  so 
that  the  condition  may  resemble  an  acute  febrile  disease  and 
last  for  several  days.  It  seems  very  probable  that  substances  more 
toxic  than  the  above-mentioned  acids  are  involved.  Weichardt 2 
claims  to  have  demonstrated  as  produced  by  muscular  fatigue  a 
toxic  substance,  which  in  structure  resembles  the  bacterial  toxins, 
and  against  which  an  antitoxin  may  be  obtained.  This  toxic 
material  is,  he  believes,  formed  from  the  proteid  molecule  in  the 
first  stages  of  its  decomposition,  as  a  side  product  which  is 
normally  protected  against  by  a  formation  of  an  antitoxin,  rather 
than  by  being  split  up  further,  as  is  the  case  with  the  rest  of  the 
proteid  molecule.3  Whether  this  work  is  confirmed  or  not,  there 
remains  the  fact  that  the  blood  of  fatigued  animals  contains 
toxic  substances,  which  Mosso  proved  as  follows :  If  blood  is 
transfused  from  an  exhausted  dog  to  a  normal  dog,  from  which 
an  equivalent  amount  of  blood  has  been  withdrawn,  this  second 
dog  will  show  the  usual  manifestations  of  fatigue. 

Mental  Fatigue. — The  chemical  changes  of  mental  fatigue 
are  not  known,  but  it  is  known  that  the  ganglion-cells  show 
marked  structural  alterations  as  a  result  of  fatigue,  chroma- 
tolysis  often  being  very  striking.  Since  lecithin  forms  so  im- 
portant a  part  of  the  nervous  system,  it  is  tempting  to  imagine 
that  in  fatigue  excessive  quantities  of  its  toxic  decomposition- 
product,  cholin,  and  the  still  more  toxic  derivative  of  cholin, 
neurin,  are  formed  in  considerable  amounts  and  cause  part,  at 
least,  of  the  intoxication.  Cholin  has  been  demonstrated  by 
Halliburton  and  Mott  and  their  co-workers,  in  the  cerebro- 
spinal  fluid,  and  also  sometimes  in  the  blood  of  patients  suffering 
from  organic  nervous  lesions,  including  such  conditions  as  dis- 
seminated sclerosis,  tabes  dorsalis,  progressive  muscular  atrophy, 

1Deut.  med.  Woch.,  1901  (27),  796. 

2  Munch,  med.  Woch.,  1904   (51),  12  and  2121;  1905  (52),  1234;  also  re- 
viewed by  Wolff-Eisner,  Cent.  f.  Bakt,  1906  (40),  634. 

3  Weichardt,  Munch,  med.  Woch.   1906  (53),  7. 


THE  POISONS  PRODUCED  IN  SUPERFICIAL  BURNS  461 

transverse  myelitis,  and  especially  in  general  paresis.1  That  it 
or  neurin  actually  is  the  cause  of  any  of  the  symptoms  of 
fatigue,  however,  has  not  been  established ;  but  Donath 2  con- 
siders cholin  an  important  factor  in  the  production  of  epileptic 
convulsions.  (Concerning  the  theories  and  literature  of  the 
subject  of  epilepsy  in  relation  to  its  pathological  chemistry  and 
to  autointoxication,  see  the  review  by  Masoin.3) 

THE  POISONS  PRODUCED  IN  SUPERFICIAL  BURNS* 

In  a  certain  proportion  of  cases  of  extensive  but  superficial 
burns,  death  follows  after  an  interval  of  from  six  hours  to  a 
few  days,  apparently  because  of  a  profound  intoxication.  As 
evidence  of  intoxication  we  have  not  only  clinical  manifesta- 
tions, such  as  delirium,  hemoglobinuria,  and  albuminuria, 
vomiting,  bloody  diarrhea,  etc.,  but,  more  convincingly,  the 
anatomical  findings  at  autopsy,  which  are  strikingly  similar  to 
those  resulting  from  acute  intoxication  with  bacterial  products. 
Bardeen  found  quite  constantly  cloudy  swelling  and  focal 
and  parenchymatous  degeneration  in  the  liver  and  kidneys ; 
softening  and  enlargement  of  the  spleen  with  focal  degenera- 
tion in  the  Malpighian  bodies ;  and  particularly  degenerative 
changes  in  the  lymph-glands  and  intestinal  follicles  resembling 
those  observed  in  diphtheria,  which  McCrae 5  considers  due  to 
proliferation  and  phagocytosis  by  the  endothelial  cells  of  the 
lymphatic  structures.  Marked  changes  are  usually  present  in 
the  blood,  consisting  of  fragmentation  and  distortion  of  the  red 
corpuscles,  hemoglobinemia,  loss  of  water  with  a  relative 
increase  in  the  number  of  corpuscles  by  from  one  to  four  mil- 
lions per  cubic  millimeter,  an  increase  in  the  blood  platelets, 
and  a  rise  in  the  number  of  leucocytes  as  high  as  30,000  to 
50,000.6  Hemoglobinuria  is  also  frequently  present,  and 
almost  constantly  gastro-intestinal  irritation  occurs,  with  ana- 
tomical evidences  of  acute  enteritis,  acute  gastritis,  and  occasion- 
ally gastric  or  duodenal  ulcers.  According  to  Korolenko,7  the 
sympathetic  nervous  system  is  seriously  involved. 

1  Halliburton,  "  Biochemistry  of  Muscle  and  Nerve,"  1904,  p.  116 ;  Donath, 
Jour,  of  Physiol.,  1905  (33),  211. 

2Zeit.  physiol.  Chem.,  1903  (39),  526. 

3  Arch,  internat.  de  Pharmacodynamie,  1904  (13),  387. 

4  Literature  given  by  Bardeen,  Johns  Hopkins  Hosp.  Eeports,  1898  (7), 
137  ;  Eyff,  Cent.  Grenzgeb.  Med.  u.  Chir.,  1901  (4),  428 ;  Pfeiffer,  Virchow's 
Arch.,  1905  (180),  367. 

5Amer.  Med.,  1901  (2),  735. 

6  Locke,  Boston  Med.  and  Surg.  Jour.,  1902  (147),  480. 

7  Cent.  f.  Path.,  1903  (10),  663. 


462  METABOLIC  ABNORMALITIES,  AUTOINTOXICATION 

It  therefore  seems  probable  that  poisons  are  formed  as  a  re- 
sult of  superficial  burns,  which  have  the  effect  of  causing  hemol- 
ysis,  and  which  are  also  cytotoxic  for  parenchymatous  cells  and 
particularly  for  nervous  tissues.  These  hypothetical  poisons 
seem  to  be  eliminated  by  the  intestines  and  kidneys,  which  are 
injured  by  the  poisons  in  their  passage  through  these  organs, 
The  attempts  to  explain  all  the  observed  effects  of  burns  as 
due  to  thrombosis  or  to  embolism  by  altered  red  corpuscles 
seem  to  have  failed,  for  the  peculiar  location  of  the  lesions 
(e.g.)  duodenal  ulcers,  necrosis  in  the  Malpighian  bodies  of 
the  spleen,  etc.)  does  not  agree  with  this  hypothesis,  and 
there  are  too  many  evidences  of  the  presence  of  some  de- 
cidedly toxic  substance  in  the  blood.  There  can  be  no  ques- 
tion that  the  poisonous  substance  or  substances  are  formed  in 
the  burned  area,  and  not  in  the  internal  organs  as  a  result 
of  hyperpyrexia,  as  shown  by  numerous  observations.  Thus, 
if  the  burned  area  is  removed  immediately  (in  narcotized 
experimental  animals),  death  will  be  prevented,  whereas  if  the 
burned  tissue  is  permitted  to  remain  for  a  few  hours,  death  will 
occur.  The  poison  appears  to  be  absorbed  from  the  burned 
area  into  the  blood,  for  if  the  circulation  is  shut  off  from  the 
burned  area,  no  intoxication  results ;  this  probably  explains  in 
part  why  deep  destructive  burns  of  small  areas,  which  are 
associated  with  local  thrombosis,  are  much  less  serious  than  a 
superficial  slight  scalding  over  a  large  area.  Apparently  the 
poison  is  produced  chiefly  or  solely  in  the  skin,  for  burning  of 
muscle  is  not  followed  by  intoxication  (Eijkman  and  Hoogen- 
huyze J).  Numerous  investigators  have  reported  finding  poison- 
ous substances  in  the  blood,  tissues,  or  urine  of  burned  men 
and  animals,  but  the  reports  disagree  widely  in  details.2  Thus 
Dietrichs  states  that  the  blood  of  burned  animals  contains 
hemolysins  and  hemagglutinins,  which  could  not  be  corroborated 
by  Burkhardt 3  or  by  Pfeiffer.4  The  latter,  however,  finds  that 
the  urine,  serum,  and  organs  of  burned  animals  contain  sub- 
stances poisonous  for  the  same  and  for  different  species,  which 
is  in  accord  with  the  results  of  numerous  earlier  investigators. 
The  poisons,  according  to  Pfeiffer  are  neurotoxic  and  necro- 

1  Virchow's  Arch.,  1906  (183),  377. 

2  Ravenna  and  Minassian  (ref.  in  Biochem.  Centr.,  1903    (1),  348)  state 
that  blood  heated  outside  the  body  to  55°-60°  is  toxic,  and  causes  the  same 
anatomical  changes  as  does  death  from  burning,  which  finding  is  corroborated 
by  Helsted  (Dissertation,  Copenhagen,  1905;   abst.  in  Nordistk  Med.   Ark., 
1906  (39),  July  11). 

3  Arch.  klin.  Chir.,  1905^(75),  845. 
*  Virchow's  Arch.,  1905  (180),  367. 


THE  POISONS  PRODUCED  IN  SUPERFICIAL  BURNS  463 

genie  in  their  properties,  and  act  without  a  period  of  incuba- 
tion ;  they  are  rapidly  weakened  on  standing  in  solution  and  by 
the  action  of  sunlight,  are  absorbed  from  the  gastro-intestinal 
tract,  are  soluble  in  water,  alcohol,  and  glycerin,  but  not  in 
chloroform  or  ether,  are  precipitated  by  HgCl2  in  acid  solution, 
and  by  phosphotungstic  acid,  and  they  are  not  volatile. 
Apparently,  according  to  Pfeiffer,  they  are  not  ptomai'ns,  nor 
yet  pyridin  derivatives,  as  many  investigators  have  contended, 
but  resemble  more  closely  the  labile  poisons  of  snake  venom. 
The  neurotoxic  substance  is  more  thermostable  than  the  necro- 
genic  substance,  which  is  very  easily  destroyed  by  heat.  Pfeiffer 
believes  it  probable  that  the  poisons  are  derived  from  the  cleav- 
age of  proteids  altered  in  composition  by  burning.  The 
hemolysis  he  attributes  to  direct  injury  of  the  blood  in  its  pas- 
sage through  the  heated  area,  and  not  to  the  action  of  poisons ; 
this  is  very  possible,  since  red  corpuscles  fragment  after  being 
heated  to  52°,  and  may  be  seriously  impaired  functionally  at 
45°.  There  are  many  authors,  indeed,  who  consider  the  blood 
changes  the  chief  cause  of  death,  but  the  weight  of  evidence  is 
in  favor  of  the  theory  of  the  development  of  toxic  substances 
in  the  burned  skin.  In  spite  of  Pfeiffer' s  researches,  however, 
the  nature  of  these  poisons  must  be  considered  as  completely 
unknown,  for  numerous  other  observers  have  described  "  pepto- 
toxins "  (Fraenkel  and  Spiegler),  ptomai'ns  (Kijanitzin,  Ajello 
and  Parascendolo),  and  pyridin  bases  (Fraenkel  and  Spiegler, 
Reiss  *).  It  remains  also  to  be  determined  if  the  poisons  are 
of  such  a  nature  that  an  immune  serum  can  be  obtained  for 
them. 

Burn  Blisters. — The  contents  of  burn  blisters  resemble  the 
fluid  of  inflammatory  edemas  generally.  K.  Morner2  found 
5.031  per  cent,  of  proteids,  which  included  1.359  per  cent,  of 
globulin  and  0.011  per  cent,  of  fibrin  ;  there  was  also  present 
a  substance  reducing  copper  oxide,  but  no  pyrocatechin. 


1  References  given  by  Pfeiffer,  loc.  cit. 
2Skand.  Arch.  Physiol,  1895  (5),  272. 


CHAPTER    XIX 

GASTRO-INTESTINAL    "  AUTOINTOXICATION  * 
AND  RELATED  METABOLIC  DISTURBANCES 

UNDER  this  heading  are  commonly  included  all  intoxications 
that  can  be  ascribed  to  the  absorption  from  the  gastro-intestinal 
tract  of  toxic  substances  that  have  been  formed  within  its  con- 
tents, either  by  the  action  of  the  digestive  ferments  or  of  putre- 
factive bacteria.  The  propriety  of  considering  such  conditions 
as  examples  of  autointoxication  is  properly  questioned,  since  it 
is  often  difficult  to  determine  whether  the  putrefaction  occurred 
within  the  body,  or  had  already  taken  place  in  the  food  before 
it  was  eaten.  But  even  those  who  would  limit  the  use  of  the 
term  autointoxication  to  intoxication  with  the  products  of  cellu- 
lar metabolism,  must  admit  the  possibility  of  products  of  metab- 
olism reentering  the  blood  from  the  contents  of  the  bowels 
through  the  intestinal  wall,  since  the  bile,  and  perhaps  also  the 
intestinal  juice,  contain  excrementitious  substances  which  may, 
in  case  of  defective  fecal  elimination,  be  reabsorbed  into  the  blood. 
Therefore,  in  gastro-intestinal  disturbances  we  have  the  possibil- 
ity of  both  true  autointoxication  and  intoxication  by  putrefactive 
products  occurring  together  in  an  inseparable  way,  and  the  com- 
mon inclusion  of  gastro-intestinal  intoxication  in  the  discussion  of 
autointoxication  would  seem  to  be  justifiable  as  well  as  expedient. 

The  sources  of  poisonous  substances  arising  in  the  gastro- 
intestinal tract  are  numerous.  They  may  be  formed  either 
from  the  food-stuffs,  or  from  the  secretions  and  excretions  of 
the  body  that  enter  the  alimentary  canal ;  and  they  may  be 
formed  either  by  the  digestive  ferments  or  by  the  bacteria  of 
the  intestinal  contents.  Hence  the  number  of  these  products  is 
enormous,  and  we  are  by  no  means  sure  that  those  that  have  yet 
been  identified  include  the  most  important  or  most  toxic.  To 
classify  the  poisonous  substances  that  are  known  to  be  formed 
in  the  alimentary  canal,  and  which  might,  under  certain  condi- 
tions, cause  an  intoxication,  is  extremely  difficult,  because  of 
the  uncertainty  of  our  information ;  but,  using  as  a  basis  the 
sources  of  the  substances,  they  may  be  classified  as  follows  :l 

1  Modified  from  Weintraud,   Ergeb.  allg.  Pathol.,   1897  (4),  1,  who  gives 
exhaustive  discussion  and  bibliography  to  that  date. 
464 


CLASSIFICATION  465 

I.     The  constituents  of  the  digestive  secretions,  including 
the  bile  salts  and  pigments,  pepsin,  and  trypsin. 
II.     Products  of  normal  digestion : 

(a)  From  proteids — proteoses,  peptones,  amino-acids. 
(6)  From  fats — fatty  acids  and  glycerin. 
III.     Products  of  putrefaction  and  fermentation : 
(a)  From  proteids : 

(1)  From  the  aromatic  radicals  (tyrosin,  phenylalanin, 

tryptophan) — indol,  skatol,  skatol  carbonic  (or 
indol  acetic)  acid,  phenol,  cresol,  dioxyphenols. 

(2)  From  the  fatty  acid  radicals — fatty  acids  (especially 

butyric  and  acetic),  acetone,  ammonia,  amino- 
acids,  carbon  dioxide,  hydrogen,  marsh-gas.  Also 
ptomai'ns  :  cadaverin,  putrescin,  ethylidendiamin. 

(3)  From     the     sulphur-containing    radicals  —  H2S, 

methyl  mercaptan,  ethyl  mercaptan,  ethyl  sulphid. 
(6)  From  carbohydrates : 

Fatty  acids,  the  following  having  been  detected — 
formic,    acetic,    propionic,    butyric,     valerian  ic, 
lactic,   oxybutyric,    and   succinic;   also   acetone, 
C02,  CH4,  H2. 
(c)  From  fats  : 

Higher  fatty  acids,  as  well  as  butyric  acid ;  also 
glycerin.  From  lecithin — cholin,  neurin,  and 
muscarin-like  bodies. 

IV.  Synthetic  products  of  bacterial  activity  (e.  g.  botulismus) 
which  cannot  properly  be  considered  as  causing  "  autointoxi- 
cation." 

L    THE  CONSTITUENTS  OF  THE  DIGESTIVE  FLUIDS 

These  call  for  but  brief  consideration,  for,  although  many  of 
them  are  known  to  be  toxic,  yet  there  is  no  evidence  that  they 
cause  autointoxication,  either  in  health  or  disease.  Both  pepsin 
and  trypsin,  especially  the  latter,  are  decidedly  toxic  when  in- 
jected experimentally  into  the  blood  (see  Enzymes,  pp.  77—75), 
but  they  do  not  appear  ever  to  pass  through  the  intestinal  wall 
in  sufficient  quantity  to  cause  harm,  although  minute  traces  may 
appear  in  the  urine ;  this  harmlessness  probably  depends  largely 
on  the  known  inhibiting  action  of  the  blood  upon  enzymes. 

The  bile  salts  are  also  toxic,  especially  hemolytic,  but  those 
that  are  reabsorbed  from  the  intestines  are  taken  back  into  the 
liver  and  reexcreted.  This  protective  arrangement  seems  to  be 
sufficient  for  all  emergencies.  The  bile-pigments  become  con- 
verted into  hydrobilirubin  through  reduction,  and  this  is  largely 

30 


466          G ASTRO-INTESTINAL  "AUTOINTOXICATION" 

absorbed  and  eliminated  as  urobilin.  Icterus  and  cholemia  do 
not  seem  ever  to  be  produced  by  absorption  of  bile-pigments  and 
bile  salts  from  the  intestines.  (See  Icterus,  pp.  405-410.) 

IL  PRODUCTS  OF  NORMAL  DIGESTION 
Proteoses  and  Peptones. — Under  normal  conditions, 
these  are  broken  up  in  the  intestinal  wall  into  the  amino-acids, 
through  the  agency  of  erepsin,  and  do  not  appear  in  the  blood 
in  appreciable  quantities.  To  be  sure,  certain  authors  claim  to 
have  found  albumose  in  normal  blood,1  but  if  present  the  amounts 
are  extremely  minute.  In  conditions  in  which  ulceration  or  other 
lesions  are  present  in  the  gastro-intestinal  tract  it  is  possible  to 
find  small  amounts  of  proteoses  in  the  urine,  probably  absorbed 
through  the  abnormal  areas,  but  not  in  quantities  sufficient  to 
account  for  any  appreciable  intoxication,  although  proteoses  are 
distinctly  toxic.  This  last  statement  has  been  much  contested, 
because  the  difficulty  of  purifying  proteoses  obtained  from  ordi- 
nary sources  has  left  open  the  possibility  that  such  toxic  effects 
as  have  been  observed  are  due  to  contaminating  substances,  and 
not  to  the  proteoses  themselves.  More  recent  work,  however, 
particularly  that  of  Under  hill,2  seems  to  have  established  affirm- 
atively the  toxicity  of  proteoses,  whether  from  animal  or  vege- 
table proteids.  Besides  the  classical  effect  of  inhibiting  the 
coagulation  of  the  blood,  the  proteoses  have  a  lymphagogue 
effect  (Heidenhain 3),  cause  a  fall  in  arterial  pressure,  cause  a 
marked  febrile  reaction,  and  in  doses  of  some  size  are  fatal  to 
experimental  animals  (rabbits  being  much  less  susceptible  than 
dogs  and  many  other  animals 4).  Locally  they  cause  a  mild  in- 
flammatory reaction,  which  is  followed  by  the  appearance  of  much 
connective-tissue  formation.5 

1  Embden  and  Knoop,  Hofmeister's  Beitr.,  1902  (3),  120;  Langstein,  ibid., 
p.  373;  Morawitz  and  Dietschy,  Arch.  exp.  Path.,  1905  (54),  88.     However, 
many  investigators  have  failed  to  find  them;   see   Abderhalden  and  Oppen- 
heimer,  Zeit.  physiol.  Chem.,  1904  (42),  155 ;  Schryver,  Biochemical  Journal, 
1906  (1),  137;  Kraus,  Zeit.  exp.  Pathol.,  1906  (3),  52. 

2  Amer.  Jour.  Physiol.,  1903  (9),  345  (literature). 

3  See  also  Nolf,  Arch,  internat.  de  Physiol.,  1906  (3),  343. 

4  According  to  Buchner  and  Geret,  Munch,  med.  Woch.,  1901  (48),  1163r 
0.2  gram  of  "  pure  peptone  "  per  kilo  kills  rabbits  in  twelve  hours. 

5  In  a  paper  appearing  in  the  Transactions  of  the  Chicago   Pathological 
Society,  1903  (5),  240,  I  published  the  observation  that  repeated  injections  of 
Witte's  "peptone"  (which  consists  chiefly  of  proteoses)  into  rabbits  led  to  the 
production  of  marked  cirrhosis  of  the  liver,  and  suggested  the  possibility  that 
proteoses  escaping  through  a  diseased  gastric  or  intestinal  wall  into  the  blood 
might  be  a  factor  in  the  production  of  cirrhosis  in  man.     Subsequent  observa- 
tions, however,  have  shown  that  repeated  injection  of  almost  any  foreign  pro- 
teid  material  (e.  g.,  emulsions  of  organs,  foreign  blood,  etc.,  used  in  immuniza- 
tion  experiments)  will  cause  a    similar  cirrhosis  in  rabbits,   which  animals, 


PROTEOSES  AND  PEPTONES  467 

According  to  most  observers,  precipitins  for  proteoses  and 
peptones  cannot  be  obtained  by  experimental  immunization, 
although  the  animal  may  show  a  distinct  increase  in  resist- 
ance ;  possibly  this  failure  is  not  due  to  a  lack  of  formation 
of  antibodies,  but  to  their  forming  a  compound  with  prote- 
oses (or  peptones)  which  is  soluble,  and  hence  no  precipitation 
results.1 

As  the  decomposition  of  the  proteid  molecule  continues,  the 
toxic  effects  of  the  resulting  substances  seem  to  decrease  along 
with  the  decreased  size  of  the  molecules.  Thus  Wolf2  found 
that  the  amino-acids  do  not  cause  a  fall  of  blood  pressure,  nor 
do  polypeptids.3 

"Alimmosuria." — If  proteoses  enter  the  blood  stream 
they  appear  in  large  part  in  the  urine,  indicating  that  the  tissues 
do  not  readily  utilize  them  in  this  form.4  Consequently,  when 
proteoses  are  produced  in  considerable  amounts  by  autolysis  of 
pathological  tissues  they  appear  in  the  urine,  and  their  presence 
is  considered  to  be  of  diagnostic  value.5  True  peptone  seems 
rarely,  and  according  to  many  observers  never,  to  appear  in  the 
urine.  (In  view  of  the  recent  observations  that  polypeptids 
often  appear  in  the  urine,  it  is  probable  that  true  peptones  also 
do.)  Albumoses,  therefore,  may  be  found  in  the  urine  when- 
ever any  considerable  amount  of  tissue  or  exudate  is  being 
autolyzed  and  absorbed,  and  it  has  been-  found  in  the  following 
conditions  :  Suppuration  of  all  kinds ;  resolution  of  pneu- 
monia ;  involution  of  the  puerperal  uterus ;  carcinoma  (two- 
thirds  of  all  cases — Ury  and  Lilienthal),  and  other  malignant 
growths  ;  febrile  conditions  with  tissue  destruction  (37.5  per 
cent,  of  all  cases,  Morawitz  and  Dietschy)6;  acute  yellow 
atrophy,  phosphorus  poisoning,  and  eclampsia;  leukemia, 

indeed,  often  spontaneously  show  this  condition  when  apparently  otherwise 
normal.  "  Peptone  "  injections  in  dogs  and  guinea-pigs  have  failed  to  cause  a 
similar  cirrhosis,  and  hence  the  value  of  these  and  all  other  rabbit  experiments 
on  cirrhosis  of  the  liver  is  very  questionable ;  however,  the  possibility  of  the 
correctness  of  the  original  conclusion  still  remains  open. 

^Sacconaghi  (Zeit.  klin.  Med.,  1903  (51),  187),  however,  claims  to  get 
precipitins  by  immunizing  against  either  albumose  or  peptones,  which  precipi- 
tins are  not  specific  for  the  substance  used  in  immunizing,  but  are  specific  for 
the  proteids  of  the  species  from  which  the  albumoses  and  peptones  are  derived. 

2  Jour,  of  Physiol.,  1905  (32),  171. 

3  Halliburton,  ibid.,  1905  (32),  174. 

*  They  may  be  partly  hydrolized  into  smaller  complexes,  however,  primary 
proteoses  being  partly  changed  to  deutero-proteoses,  and  the  latter  partly  to  pep- 
tones (Chittenden,  Mendel,  and  Henderson,  Amer.  Jour.  Physiol.,  1899  (2),  142 ). 

3  See  Yarrow,  Amer.  Med.,  1903  (5),  452;  Ury  and  Lilienthal,  Arch.  f. 
Verdauungskr.,  1905  (11),  72;  Senator,  International  Clinics,  1905  (4,  series 
14),  85. 

6  Arch.  f.  exp.  Path.  u.  Pharm.,  1905  (54),  88. 


468         G ASTRO-INTESTINAL  "AUTOINTOXICATION" 

especially  under  x-ray  treatment ;  absorption  of  simple  and 
inflammatory  exudates ;  and  ulcerating  pulmonary  tuberculosis. l 

It  is  possible  that  some  of  the  symptoms  of  these  conditions 
are  due  to  intoxication  with  proteoses,  for  0.07  to  0.1  gram 
deutero-albumose  will  cause  a  febrile  reaction  in  a  healthy  man,2 
but  probably  their  amount  is  usually  too  small  to  cause  appreci- 
able effects.3  It  is  well  known,  however,  that  the  characteristic 
rise  of  temperature  following  the  injection  of  tuberculin  into 
tuberculous  individuals  is  also  produced  if  minute  quantities  of 
proteose  solutions  are  injected  in  place  of  tuberculin  ;  therefore, 
proteoses  arising  from  autolysis  in  tuberculosis  may  be  of 
importance  in  causing  fever  and  other  symptoms.4 

The  so-called  "  Bence-Jones  albumose "  that  appears  in  the 
urine  of  patients  with  multiple  bone-marrow  tumors  is  not  a 
true  albumose,  but  is  more  closely  related  to  the  simple  pro- 
teids,  and  is  discussed  under  the  head  of  "  Chemistry  of 
Tumors/'  pp.  427-430. 


m.  PRODUCTS  OF  PUTREFACTION  AND  FERMENTATION5 

We  may  perhaps  gain  some  appreciation  of  the  enormous 
amount  of  bacterial  action  that  goes  on  in  the  normal  intestinal 
digestive  processes  by  considering  the  fact  that  as  much  as  one- 
third  of  the  total  weight  of  the  solids  of  normal  feces  may  consist 
of  bacteria  (Strasburger),  their  proportion  being  increased  in 
diarrheal  disorders  and  decreased  in  constipation.  They  attack 
all  food-stuffs,  and  among  the  decomposition -products  formed 
through  their  activity  are  undoubtedly  many  of  considerable 
toxicity.  Most  of  the  products  of  intestinal  putrefaction  that 
have  as  yet  been  isolated  are,  however,  not  extremely  poisonous ; 
but  many  of  them  are  toxic  to  some  degree,  and  their  long- 
continued  absorption  may  well  lead  to  serious  disturbances. 
Considering  them  first  according  to  their  origin  and  chemical 
nature,  we  take  up  first  the  products  of: 

1  See  Parkinson,  Practitioner,  1906  (76),  2i9. 

2  See  Matthes,  Arch,  exper.  Path.  u.  Pharm.,  1895  (36),  437. 

3  In  a  series  of  unpublished  experiments  I  was  unable  to  cause  amyloid  de- 
generation in  rabbits  by  protracted  intoxication  with  proteose  solutions. 

4  Simon,  Arch.  exp.  Med.,  1903  (49),  449.     Concerning  relation  of  tuber- 
culin to  proteoses  see  review  by  Jolles  in  Ott's  "  Chemische  Pathol.  der  Tuber- 
culose." 

5  Complete  bibliography  given  in  the  resume  on  "  Intestinal  Putrefaction  " 
by  Gerhardt,  Ergebnisse  der  Physiol.,  1904  (III,  Abt.  1),  107. 


PROTEID  PUTREFACTION  469 

A.    PROTEID  PUTREFACTION 

(1)    SUBSTANCES  DERIVED  FROM  THE  AROMATIC  RADICALS  OF 
THE  PROTEID  MOLECULE 

In  the  proteid  molecule  are  contained  the  following  ammo- 
acids  with  an  aromatic  nucleus  : 

Tyrosin,  HO/    \CH2  —  CH  —  COOH, 

Phenylalanin,  /~^>CH2  —  CH  —COOH, 


Tryptophan,1  \_/~C  ~~  CHz  ~~  CH  "  COOH 

\       >CH 


V 

H 

/COOH 
or,  <      >-C-CH-CH2-NHr 


N 
H 

In  the  intestinal  contents  have  been  found  a  number  of  sub- 
stances that  are  undoubtedly  derived  from  these  aromatic  radicals. 
They  are  (1)  phenol, 

OH, 

which  is  formed  in  small  quantities,  presumably  from  tyrosin, 
as  also  is  the  closely  relate^  (2)  paracresol, 

HO/    NcH3, 
and  also  (3)  para-oxyphenyl  acetic  acid, 

HO^~^>CH2  —  COOH, 
and  (4)  para-oxyphenyl-propionic  acid, 

HO\         )CH2  —  CH2  —  COOH. 

1  The  correct  structural  formula  for  tryptophan  has  not  yet  been  finally 
determined,  but  the  two  formulae  given  above  are  as  proposed  by  Ellinger  (Ber. 
deut.  Chem.  Gesellsch.,  1904  (37),  1801).  The  formula  originally  proposed  by 
Hopkins  and  Cole  cannot  be  considered  as  correct  in  view  of  Ellinger'a 
observations.  For  a  full  discussion  of  this  subject  see  Mann's  "Chemistry  of 
the  Proteids,"  p.  51. 


470        GASTRO-INTESTINAL  "AUTOINTOXICATION" 

From  the  tryptophan  are  formed  numerous  important  sub- 
stances, as  follows  : 

/NH2 

—  CH2  —  CH  —  COOH, 

)CH 

NH 

(tryptophan) 

readily  yields,  through  splitting  off  the  NH2  group  and  addition 
of  H,  indol  propionic  acid  (formerly  incorrectly  called  skatol 
acetic  acid),  which  is 

— CH2  — COOH, 


X>CH 
NH 

and  from  which  in  turn  may  readily  be  formed  indol  acetic  acid 
(erroneously  called  skatol  carboxylic  acid),  which  is 


Both  of  these  substances  have  been  found  in  the  intestinal  con- 
tents. From  these  substances  are  formed  the  better  known 
skatol, 


and  indol, 

H 


In  dogs,  but  not  in  man,  kynurenic  acid, 


— C.OH 

x    Racoon, 

N=CH 
is  also  formed  from  tryptophan.1 

The  greatest  interest  concerning  these  bodies  arises  from  the 
fact  that  after  they  are  absorbed  from  the  intestine  they  become 
combined  with  sulphuric  or  glycuronic  acid,  and  are  excreted  in 
the  urine  as  salts  of  these  acids  ;  consequently  the  amount  of 
sulphuric  acid  appearing  in  the  urine  in  such  organic  combi- 
nation ("  ethereal  sulphuric  acid ")  is  considered  as  an  index 
1  See  Ellinger,  Zeit.  physiol.  Chem.,  1904  (43),  325. 


AROMATIC  DERIVATIES  OF  PROTEWS  471 

of  the  amount  of  intestinal  putrefaction.  In  the  case  of  indol 
and  skatol,  which  have  no  hydroxyl  group,  a  preliminary  oxi- 
dation occurs,  whereby  indol  is  converted  into  indoxyl. 


—  C.OH 

>CH, 


and  skatol  into  skatoxyl, 


\ 

and  they  are  then  combined  with  sulphuric  or  glycuronic  acid, 
as  follows : 


C  —  iOH  +  H|O  —  SO2—  OK    —     <^     y— C  — O  —  SOj  —  OK. 
/CH  \        /CH     (indican) 

By  far  the  greater  part  of  these  aromatic  substances,  when 
excreted  in  the  urine,  is  combined  with  sulphuric  acid,  and 
but  a  small  part  with  glycuronic  acid ;  but  in  case  the 
amount  of  sulphuric  acid  available  is  too  small  to  com- 
bine with  all  the  aromatic  radicals  entering  the  blood,  a 
large  amount  of  the  glycuronic  acid  compound  appears  in  the 
urine  (e.  g.,  after  therapeutic  administration  of  phenol,  cresol, 
thymol,  camphor,  etc.).  Both  the  preliminary  oxidation  and 
the  combining  with  acids  seem  to  occur  chiefly  in  the  liver,  this 
process  constituting  one  of  the  most  important  of  the  many  pro- 
tective offices  of  that  organ,  since  the  resulting  compounds  are 
much  less  toxic  than  are  the  original  substances.  Herter  and 
Wakeman1  have  shown  that  living  cells  have  the  power  of 
acting  upon  indol  and  phenol  (and  presumably  upon  the  rest  of 
this  group)  in  such  a  way  that  they  cannot  be  recovered  by  dis- 
tillation. Most  active  in  this  respect  is  the  liver,  then  in  order 
come  kidney,  muscle,  blood,  and  brain.  The  change  seems  to 
be  a  loose  chemical  combination  with  the  protoplasm  of  the 
cells,  and  the  power  of  the  tissues  to  bring  about  this  combina- 
tion is  not  greatly  decreased  by  serious  pathological  changes  in 
the  organs  (e.  g.,  ricin  poisoning2). 

Indol. — This  is  probably  the  most  important  member  of  this 
group  of  substances,  the  striking  color  of  its  derivatives  making 
its  detection  in  the  urine  easy,  so  that  it  is  generally  used  as  the 

1  Jour.  Exper.  Med.,  1899  (4),  307. 

2  For  further  discussion  of  this  topic,  see  "  Chemical  Defences  against  Poisons 
of  Known  Composition,"  Chapter  vii. 


472        G ASTRO-INTESTINAL  "AUTOINTOXICATION" 

most  available  index  of  the  amount  of  putrefaction  that  is  occur- 
ring in  the  intestines.  The  greatest  quantities  are  found  when 
intestinal  putrefaction  is  marked,  especially  in  intestinal  obstruc- 
tion involving  the  small  intestine ;  obstruction  of  the  large 
intestine,  as  JafFe  first  demonstrated,  does  not  cause  marked 
indicanuria  unless  the  stagnation  involves  the  ileum,  as  it  may 
in  the  latter  stages  of  obstruction.  There  can  be  no  question  that 
the  indican  of  the  urine  is  derived,  at  least  in  part,  from  the  indol 
formed  in  the  intestine,  for  administration  of  indol  by  mouth  to 
either  animals  or  man  causes  a  considerable  increase  in  the 
indican  present  in  the  urine ;  however,  but  40  to  60  per  cent, 
can  be  recovered  in  this  way,  the  rest  apparently  being  oxidized 
to  other  compounds,  part  of  which  may  also  appear  in  the  urine.1 
Whether  part  of  the  urinary  indican  is  derived  from  tryptophan 
liberated  during  intracellular  proteid  metabolism,  and  not  from 
intestinal  putrefaction,  has  long  been  a  disputed  point  among 
physiological  chemists.2  The  demonstration  by  Ellinger  and 
Gentzen  3  that  tryptophan,  when  fed  or  injected  subcutaneously 
causes  no  increase  in  urinary  indican,  whereas  its  injection  into 
the  cecum  causes  much  indicanuria,  would  indicate  that  indol  is 
formed  from  tryptophan  only  through  putrefaction,  and  not  in 
cellular  metabolism.  Other  experiments  support  the  same  view.4 
However,  it  is  possible  that  part  of  the  indican  present  in  the 
urine  during  conditions  associated  with  gangrene,  putrid  cancers, 
putrid  placentas,  or  putrid  purulent  exudates  may  be  derived 
from  these  decomposing  materials. 

Probably  the  chief  agent  in  the  formation  of  indol  in  the 
intestines  and  in  putrid  tissues  is  the  colon  bacillus,  which,  as 
is  well  known,  produces  indol  in  ordinary  culture-media. 

Toxicity  of  Indol. — Although  the  toxicity  of  indol  seems  to 
be  relatively  slight,  and  this  toxicity  is  further  reduced  by  the 
conversion  of  indol  into  indoxyl  and  indican,  yet  Herter 5 
found  that  administration  to  healthy  men  of  indol  in  quantities 
of  0.025  to  2  grams  per  day  caused  frontal  headache,  irritability, 
insomnia,  and  confusion  ;  the  continued  absorption  of  enough 
iudol  to  cause  a  constant  strong  reaction  for  indican  in  the  urine 
is  sufficient  to  cause  neurasthenic  symptoms.  Lee6  has  also 

1  If  gelatin  is  substituted  for  proteids  in  the  dietary,  indican  is  not  excreted, 
because  gelatin  does  not  contain  tryptophan  (Underbill,  Amer.  Jour.  Physiol., 
1904  (12),  176). 

2  Literature  by  Gerhardt,  Ergeb.  der  Physiol.,  1904  (III,  Abt.  1),  131. 
3 Hofmeister's  Beitr.,  1903  (4),  171. 

4 See  Scholz,  Zeit.  physiol.  Chem.,  1903  (38),  513;  Underbill,  loc.cit. 

5  New  York  Med.  Jour.,  1898  (68),  89. 

6  Jour.  Amer.  Med.  Assoc.,  1906  (46),  1499. 


AROMATIC  DERIVATIVES  OF  PROTEIDS  473 

demonstrated  that  indol,  skatol,  and  methyl  mercaptan  cause 
muscles  to  react  to  stimuli  like  fatigued  muscles.  Normal  urine 
contains  but  about  12  milligrams  of  indican  per  day,  which 
amount  is  so  insignificant  in  proportion  to  the  above-mentioned 
doses  that  were  found  necessary  to  produce  symptoms,  that  we 
may  well  doubt  the  occurrence  of  noticeable  intoxication  from 
this  substance  under  ordinary  conditions.  Nesbitt1  states  that 
twenty  times  as  much  indol  or  skatol  as  are  excreted  daily  by 
an  adult  man  may  be  injected  into  the  jugular  vein  of  a  dog 
of  four  kilos  without  causing  appreciable  effects.  Richards 
and  Rowland,  however,  have  recently  demonstrated  the  possi- 
bility that  defective  oxidation  of  substances  of  this  group  may 
permit  of  intoxication.2 

Other  Aromatic  Compounds. — Skatol  seems  to  accom- 
pany indol  in  small  amounts,  but  apparently  in  no  constant 
quantitative  relation.  Although  formed  in  larger  quantities  in 
the  intestines,  it  is  but  slightly  absorbed. 

Indol-acetic  acid  appears  in  the  normal  urine  in  extremely 
minute  quantities,  and  is  increased  in  the  same  conditions  as  are 
indol  and  skatol. 

Phenol  appears  in  the  urine  normally  in  very  minute  quan- 
tities— from  0.005  to  0.07  grams  per  day,  according  to  various 
observers.  Much  more  is  undoubtedly  formed  in  the  intestines, 
for  but  a  small  fraction  of  phenol  given  by  mouth  (2  to  3  per 
cent.,  according  to  Munk)  appears  in  the  urine  as  a  sulphuric- 
acid  compound  ;  part  of  the  rest  is  oxidized  to  hydrochinon  and 
pyrocatechin,  C6H4  (OH)2,  and  eliminated  as  ethereal  sulphates. 
The  largest  quantities  are  found  in  the  same  conditions  as  indican, 
except,  of  course,  in  "  carbolic-acid  "  poisoning,  when  the  amounts 
may  be  so  great  that  practically  all  the  sulphuric  acid  in  the 
urine  is  in  this  organic  combination,  much  of  the  phenol  under 
these  conditions  being  also  combined  with  glycuronic  acid.3 

Cresol  (chiefly  paracresol),  para-oxyphenyl  acetic  acid,  and 
para-oxyphenyl  propionic  acid  appear  under  similar  conditions, 
except  that  the  two  oxy-acids  are  possibly  also  formed  within 
the  body  through  cellular  metabolism,  as  they  have  been  found 
present  in  the  urine  independent  of  intestinal  putrefaction. 
Probably  part  of  the  benzoic  acid  that  appears  in  the  urine 
combined  with  glycocoll,  as  hippuric  acid,  is  derived  from 
intestinal  putrefaction.4 

1  Jour.  Exper.  Med.,  1899  (4),  5.  2See  note  in  Science,  1906  (24),  979. 

3  See  the  observations  of  Wohlgemuth  and  of  Blumenthal  (Biochem.  Zeit- 
schrift,  1906  (1),  134),  on  the  detoxication  of  lysol  and  similar  poisons. 

4  See  Prager,  Med.  News,  1905  (86),  1025;  Magnus-Levy,  Munch,  med. 
Woch.,  1905  (52),  2168. 


474       G  ASTRO-INTESTINAL  "AUTOINTOXICATION" 


ALKAPTONURIA  1 

Alkaptonuria  may  be  appropriately  considered  in  this  connec- 
tion, since  it  depends  on  an  abnormal  metabolism  of  the  aromatic 
groups,  tyrosin  and  phenylalanin,  which  are,  partly  at  least,  split 
out  of  the  proteid  molecule  in  the  intestine.  This  condition  is 
characterized  by  the  tendency  of  the  urine  to  turn  dark  on 
exposure  to  air,  due  to  the  presence  in  it  of  two  aromatic  sub- 
stances, homogentisic  and  uroleucic  acids.2  It  is  of  rare  occur- 
rence, persists  throughout  life  with  but  little  apparent  effect 
upon  the  health  of  the  individual,  and  is  often  hereditary,  being 
grouped  by  Garrod  3  along  with  cystinuria  and  albinism  as  a 
"  chemical  malformation  "  of  hereditary  origin.  The  relation 
of  these  aromatic  bodies  to  the  aromatic  constituents  of  the 
proteids  is  best  shown  by  comparing  their  structural  formulae  :  4 


Phenylalanin,  <CH2  -  CHNH2  -  COOH. 

Tyrosin,  HO-/^)cH3-CHNH2-COOH. 

_OH 
Uroleucic  acid,  /    \CH2—  CHOH—  COOH. 


OH 
Homogentisic  acid,  CH2  —  COOH. 


Apparently  the  condition  depends  upon  an  abnormality  in  the 
intermediary  metabolism,  and  not  upon  an  abnormal  formation 
of  homogentisic  acid  through  intestinal  putrefaction,  as  was  at 
first  believed.  This  abnormality  consists  not  in  the  excessive 
formation  of  homogentisic  and  uroleucic  acids,  but  in  a  lack  of 
ability  on  the  part  of  the  alkaptonuric  individual  to  split  open 


byFalta,  Biochem.  Centralblatt,  1904  (3),  174,  and 
)4  (81),  231.    Also  see  Abderhalden,  "  Lehrbuch  der 


1  Re'sume'  and  literature 
Deut.  Arch.  klin.  Med.,  1904" 
Physiologischen  Chemie,"  Berlin,'  1906,  pp.  294-298. 

2  It  should  be  mentioned  that  hydrochwon,  when  present  in  the  urine  (usually 
after  ingestion  of  large  quantities  of  phenol),  may  also  turn  dark  on  exposure 
to  air ;  and  melanin  may  be  excreted  as  a  chromogen  which  turns  dark   on 
exposure,  by  patients  with  melanotic  tumors  orochronosis  (q.  v.). 

~z  Lancet,  1902  (ii),  1616. 

4  Concerning  the  formation  of   homogentisic  acid  from   tyrosin  in  plant 
tissues,  see  Schulze  and  Castoro,  Zeit.  physiol.  Chem.,  1906  (48),  396. 


ALKAPTONURIA  475 

the  benzene  ring.  Tyrosin  and  phenylalanin  seem  normally 
to  first  suffer  a  splitting  out  of  the  nitrogen  radical  from  the 
alanin  side-chain,  and  then  to  be  oxidized  into  uroleucic  and 
homogentisic  acids,  following  which  changes  comes  a  disintegra- 
tion of  the  benzene  ring,  with  subsequent  complete  oxidation. 
The  alkaptonuric  accomplishes  the  conversion  into  the  oxy-acid, 
but  the  process  stops  there.  Consequently  the  administration 
of  tyrosin  or  phenylalanin,  or  of  tyrosin-rich  foods — i.  e., 
proteids — causes  a  marked  increase  in  the  amount  of  homo- 
gentisic acid  eliminated  in  the  urine  (uroleucic  acid,  which  is  the 
precursor  of  homogentisic  acid,  has  been  observed  abundantly  in 
but  one  case) ;  indeed,  this  increase  is  almost  quantitative. 
Normal  individuals  when  given  these  substances,  or  homogen- 
tisic acid  itself,  destroy  them  completely,  so  that  the  latter  does 
not  appear  at  all  in  the  urine.  If  alkaptonurics  are  kept  without 
proteid  food  for  some  time,  the  elimination  of  alkaptonuric  acids 
goes  on,  although  in  diminished  amounts,  indicating  that  the 
aromatic  amino-acids  formed  in  tissue  katabolism  also  fail  to  be 
destroyed  and,  therefore,  appear  in  the  urine  as  these  derivatives. 
As  gentisic  acid, 

OH 
;—  COOH, 


HO 

when  given  by  mouth,  is  also  eliminated  unchanged  by  alkap- 
tonurics, although  completely  destroyed  by  normal  individuals, 
it  seem  evident  that  the  difficulty  in  metabolism  affects  the  ben- 
zene ring  itself,  and  does  not  depend  upon  the  character  of  the 
side-chain.  Normal  organisms  seem  to  be  capable  of  destroying 
only  such  aromatic  compounds  as  pass  through  a  stage  of  homo- 
gentisic acid  in  being  oxidized,  which  indicates  that  the  benzene 
ring  can  be  broken  up  only  when  oxidized  in  this  particular 
manner  (the  2,  5  position) ;  the  alkaptonuric  differs  in  being 
unable  to  break  up  even  this  form  (Falta). 

In  some  cases  of  alkaptonuria  a  pigmentation  of  the  carti- 
lages also  occurs,  ochronosis,  but  the  association  is  not  constant ; 
ochronosis  may  occur  without  alkaptonuria,  and  conversely. 
(See  "Ochronosis/'  page  397.) 

(2)  SUBSTANCES   ARISING   FROM   THE  FATTY  ACID   RADICALS 
(AMINO-ACIDS)  OF  PROTEIDS 

As  stated  in  the  introductory  chapter,  the  proteid  molecule 
consists  of  a  combination  of  a  great  number  of  organic  acids, 
of  various  sorts,  all  of  which  have  as  a  common  characteristic 


476        GASTRO-INTESTINAL  "AUTOINTOXICATION" 

the  presence  of  an  NH2  group  attached  to  the  carbon  atom  nearest 
the  acid  radical,  the  a  position  ;  thus,  R  —  CHNH2  —  COOH. 
A  few  of  the  ammo-acids  contain  an  aromatic  group,  and  the 
relation  of  these  to  intestinal  decomposition  has  been  considered 
above.  The  greater  number  have  a  simple  fatty  acid  radical 
(the  simplest  amino-acid  being  glycocoll,  CH2NH2  —  COOH), 
and  from  them  are  derived  by  intestinal  putrefaction  substances 
that  are,  for  the  most  part,  chemically  simple  and,  as  far  as 
known,  pathologically  unimportant. 

Fatty  acids  may  readily  be  formed  from  them  by  splitting  out 
of  the  NH2  group  ;  thus  acetic  acid  may  be  formed  from  glycocoll, 
propionic  acid  from  alanin,  etc.  Apparently  butyric  and  acetic 
acid  are  the  acids  most  commonly  formed  in  this  way.  Gaseous 
derivatives,  such  as  hydrogen,  ammonia,  carbon  dioxide,  and 
marsh-gas  are  also  produced.  Acetone  is  perhaps  formed  from 
these  fatty  acids  ;  it  is  often  present  in  the  intestinal  contents, 
but  may  come  from  other  sources. 

Diatnins.  —  Of  more  interest  are  the  substances  that  are 
formed  from  the  amino-acids  by  bacterial  action,  which  still  retain 
their  nitrogen  radicals  —  the  plomains.  Two  of  these,  the  diamins 
putrescin,  NH2(CH2)4NH2  ,  and  cadaverin,  NH2(CH2)5NH2 
are  of  particular  interest  i  because  they  have  been  observed  in 
the  feces  and  urine  of  persons  with  cystinuria.  The  stools  in 
cholera  also  seem  to  contain  these  ptomains  frequently.  Their 
etiological  relation  to  the  cystinuria  is  no  longer  accepted,  how- 
ever, and  their  toxicity  is  slight.  They  are  probably  derived 
from  the  diamino-acids  of  the  proteid  molecule,  putrescin  being 
closely  related  to  ornithin?  and  is  probably  formed  from  it  as 
follows  : 


NH2  NH2  NH2  NH2 

CH2  —  CH2  —  CH2—  CH  —  COOH  =  CH2  —  CH2  —  CH2—  CH2  +  CO2, 

(ornithin)  (putrescin) 

while  cadaverin  is  probably  formed  from  lysin, 

NH2  NH2  NH2  NH2 

CH2  —  (CH2)3—  CH  —  COOH  =  CH2  —  (CH2)3  —  CH2  -f  CO2. 

(lysin)  (cadaverin) 

,NH2 
Eihylidendiamin,    CHSCH/  which    is   somewhat  toxic, 


1  For  discussion    of  formation  and  properties  of  these  two  ptomains,  see 
Vaughn  and  Novy's  "  Cellular  Toxins." 

2  Ornithin  forms  part  of  the  arginin  molecule,  which  is  the  most  univer- 
sally present  of  all  the  amino-acids,  ornithin  being  formed  when  urea  is  split 
from  arginin. 


SULPHUR-CONTAINING  SUBSTANCES  477 

has  also  been  detected  in  the  contents  of  the  gastro-intestinal 
tract. 

Apparently  these  substances  are  absent  from  normal  feces, 
but  this  does  not  exclude  the  possibility  of  their  normal  forma- 
tion, absorption,  and  destruction.  There  is  no  evidence  that 
they  ever  cause  symptoms  or  pathological  alterations. 


(3)    SUBSTANCES  ARISING   FROM   THE    SULPHUR-CONTAINING 
RADICAL   OF   THE    PROTEID 

Most  if  not  all  of  the  sulphur  in  the  proteid  molecule  seems 
to  be  contained  in  the  amino-acid,  cystin,  which  has  the 
following  composition  : 

g  _  CH2  —  CHNH2  —  COOH 
S  _  CH2  —  CHNH2  —  COOH. 

From  this  is  formed  the  hydrogen  sulphide  of  the  intestinal 
gases,  of  which  about  0.058-0.066  gram  is  present  in  each 
one  hundred  grams  of  normal  colon  contents.  Although 
Senator  has  described  a  case  in  which  an  intoxication  with  H2S 
of  intestinal  origin  occurred,  this  gas  seems  not  to  be  a  frequent 
cause  of  intoxication,  and  Senator's  case  stands  almost  alone. 
Under  normal  conditions  H2S  does  not  appear  in  the  urine,  any 
that  may  be  absorbed  probably  being  oxidized  to  SO4.  If 
enough  H2S  should  enter  the  blood  so  that  it  was  not  completely 
destroyed,  it  might  well  cause  harm,  for  it  is  decidedly  toxic, 
particularly  affecting  the  nervous  system ;  but  we  have  no 
evidence  that  this  often  happens.  Van  der  Bergh  l  has  observed 
cases  of  intestinal  obstruction  in  which  the  presence  of  sulphemo- 
globin  in  the  patient's  blood  was  demonstrated. 

Methyl  mercaptan,  CH3SH,  has  also  been  found  in  the  feces, 
although  it  seems  not  to  be  abundantly  or  constantly  present, 
according  to  Herter,2  who  found  also  that  mixed  bacteria  from 
normal  feces  rarely  produce  mercaptan  in  cultures.  However, 
bacteria  from  the  feces  of  persons  suffering  with  various  diseases 
often  produce  mercaptan.  Ethyl  mercaptan,  C2H5SH,  and  ethyl 
sulphide,  C2H5 — S — C2H. ,  have  also  been  described  as  fecal 
constituents.  It  is  not  known  that  the  mercaptans  are  a  cause 
of  intoxication. 

1  Deut.  Arch.  klin.  Med.,  1905  (83),  86. 

2  Jour.  Biol.  Chem.,  1906  (1),  421. 


478        G ASTRO-INTESTINAL  "AUTOINTOXICATION 


CYSTIN  AND  CYSTINURIA  1 

The  presence  of  cystin  in  the  urine  has  been  observed  in  a 
number  of  cases,  and  when  present  at  all  it  is  usually  present 
in  considerable  quantities.  Because  of  its  slight  solubility  it 
appears  as  a  deposit  of  hexagonal  crystals,  and  frequently 
forms  cystin  concretions  (g.  v.)  in  the  urinary  bladder.2 
Baumann  and  others  observed  that  in  cystinuria  the  urine 
often  contains,  besides  the  cystin,  the  diamins  cadaverin  and 
putrescin,  which  are  both  formed  in  the  intestines  through 
putrefaction,  and  they  naturally  suspected  that  cystin  arose  in  the 
same  way.  Another  view  was  that  the  diamins  interfered 
with  the  oxidation  of  sulphur  in  the  body,  so  that  it  was 
eliminated  in  the  unoxidized  form  of  cystin.  But  it  has  been 
demonstrated  that  neither  of  these  hypotheses  is  correct,  for  (1) 
cystin  could  not  be  found  in  the  feces  ;  (2)  if  given  by  mouth,  it 
is  completely  oxidized,  and  causes  only  the  appearance  of 
excessive  amounts  of  sulphates  in  the  urine;  (3)  cystinuria 
has  been  observed  to  occur  independent  of  the  presence  of 
the  diamins,3  and  not  to  be  modified  or  caused  by  their  adminis- 
tration or  pathological  formation.  The  view  now  prevalent 
is  that  the  cystin  that  escapes  in  the  urine  in  cystinuria  is  not 
derived  from  intestinal  putrefaction,  but  is  formed  in  the  tissues 
from  the  proteid  molecule,  and  fails  to  be  further  decomposed 
because  of  some  anomaly  of  metabolism.  This  view  is  sup- 
ported by  the  fact  that  cystinuria  often  appears  to  be  an  hered- 
itary disease,  occurring  in  families  for  several  generations ;  it 
is  independent  of  the  diet,  cystin  appearing  even  if  proteids  are 
withheld,  and  also  independent  of  intestinal  putrefaction.  It 
having  been  found  that  leucin  and  tyrosin  may  also  occur  in  the 
urine  in  cystinuria,4  it  seems  probable  that  this  condition 
depends  upon  a  general  abnormality  of  proteid  metabolism.5 

1  Literature  concerning  cystin  given  by  Friedmann,  Ergebnisse  der  Physiol., 
1902  (I,  Abt.  1),  15  ;  and  by  Mann,  Chemistry  of  the  Proteids,  pp.  56-64.  Cys- 
tinuria reviewed  by  Bodtker,  Zeit.  physiol.  Chem.,  1905  (45),  393. 

2Abderhalden  (Zeit.  physiol.  Chem.,  1903  (38),  557)  has  described  a  case 
in  a  child  in  which  the  organs  were  infiltrated  with  masses  of  the  cystin  crys- 
tals. 

3  See  Garrod  and  Hartley,  Jour,  of  Physiol.,  1906  (34),  217. 

4  Abderhalden  and  Schittenhelm,  Zeit.  physiol.  Chem.,  1905  (45),  468. 

5 The  question  as  to  the  identity  of  proteid  cystin  and  " stone  cystin"  raised 
by  Loewi  and  Neuberg  seems  to  have  been  decided  affirmatively.  As  to  the 
condition  of  general  proteid  metabolism  in  cystinuria,  the  discussion  is  at  the 
present  time  too  unsettled  to  permit  of  consideration.  For  discussion  and 
literature  see  Alsberg  and  Folin,  Amer.  Jour.  Physiol.,  1905  (14),  54;  also 
Marriott  and  Wolf,  Amer.  Jour.  Med.  Sci.,  1906  (131),  197  ;  Garrod  and  Hart- 
ley, lac.  tit. 


PRODUCTS  OF  FERMENTATION  OF  CARBOHYDRATES  479 

The  relation  of  the  diamins  to  the  condition  is,  however,  very 
uncertain.  Cystin  does  not  seem  to  exert  any  toxic  effect,  and 
patients  with  cystinuria  do  not  usually  appear  to  suffer  greatly 
from  the  abnormal  metabolism,  the  chief  trouble  observed  being 
due  to  the  formation  of  the  concretions  in  the  bladder.  Some- 
times in  children,  however,  emaciation  and  early  death,  with- 
out other  apparent  cause,  have  been  observed,  and  may  be 
due  to  the  metabolic  anomaly. 

B.      PRODUCTS  OF  FERMENTATION  OF  CARBOHYDRATES 

These  include  practically  all  the  members  of  the  fatty  acid 
series,  from,  formic  acid  to  valerianic  acid;  and  the  oxy-acids, 
lactic,  succinic,  and  oxybutyric ;  also,  oxalic  acid,  acetone,  ethyl 
alcohol,  and  the  following  gases,  CO2,  CH4,  H2.  For  the  most 
part,  the  various  organic  acids  are  absorbed  through  the  intes- 
tinal walls,  and  are  oxidized  completely  in  the  tissues  without 
causing  any  harm  whatever.  The  possibility  that  acid  intoxica- 
tion may  be  produced  in  this  way  has  been  suggested,  but  it  is 
generally  believed  that  this  does  not  occur,  except  possibly  in 
infants.  Lactic  and  butyric  acids  are  formed  particularly  in 
gastric  fermentations  in  persons  with  deficient  hydrochloric  acid, 
motor  insufficiency,  or  organic  obstruction.  Most  of  the  disturb- 
ances observed  in  these  conditions  seem  to  be  due  to  distention  of 
the  stomach  with  gas,  chiefly  CO2,  which  is  formed  during  the 
fermentation.  It  is  possible,  however,  that  the  organic  acids 
exercise  some  irritant  effects  on  the  mucous  membrane ;  and 
they  may  also  cause  diarrhea,  lactic  and  acetic  acid  often  being 
present  in  diarrheal  discharges  due  to  excessive  feeding  with 
carbohydrates  (Herter). 

These  acids  or  their  salts  do  not  appear  in  the  urine,  unless 
possibly  as  minute  traces,  except  the  oxalic  acid.  Minute 
quantities  (0.02  gm.  per  day)  of  this  substance  are  present  in 
normal  urine,  but  larger  quantities  (oxaluria)  seem  to  depend 
either  upon  the  taking  of  food  containing  much  oxalic  acid 
(rhubarb,  spinach,  etc.)  or  upon  excessive  gastric  fermentation 
of  carbohydrates  (Baldwin l ),  and  perhaps  upon  excessive  de- 
struction of  purin  bodies,  from  which  oxalic  acid  may  be  derived. 
Probably  the  small  quantities  of  oxalic  acid  thus  formed  do  not 
cause  toxic  effects,  and  are  important  chiefly  as  causing  urinary 
concretions  of  calcium  oxalate,.  although  there  is  evidence  that 
long-continued  excretion  of  oxalic  acid  may  cause  renal  lesions. 
(See  also  consideration  of  oxalate  calculi,  pages  382,  383.) 

1  Jour.  Exp.  Med.,  1900  (5),  27. 


480       GASTRO-INTESTINAL  "AUTOINTOXICATION" 
C.     PRODUCTS  OF  THE  DECOMPOSITION  OF  FATS 

These  differ  but  little  in  nature  from  the  products  of  carbo- 
hydrate fermentation,  the  large  fatty  acid  molecules  being 
broken  down  to  smaller  ones.  In  infants  these  fatty  acids  have 
been  believed  to  be  a  cause  of  acid  intoxication  and  acetonuria,1 
but  probably  they  are  seldom,  if  ever,  of  pathological  impor- 
tance. 

It  is  quite  otherwise  with  the  products  of  decomposition  of  leci- 
thin? From  its  molecule  is  split  off  the  ptomai'n  cholin, 

(CH3)3=  N  —  CH2  —  CH2OH, 
OH 

which  is  easily  oxidized  into  a  highly  poisonous  compound, 
isomeric  with  muscarin,  or  by  losing  a  molecule  of  water  it 
forms  neurin, 

(CH3)3  =  N-CH  =  CH2, 

I  •  > 

OH 

which  is  also  very  poisonous  (discussed  under  "  Ptomai'ns," 
Chap.  iv).  It  has  been  demonstrated  by  Nesbitt 3  that  in  the 
contents  of  obstructed  intestines  of  dogs  that  have  been  fed 
lecithin-rich  food  (eggs)  both  cholin  and  neurin  may  be  found 
free,  and  Kutscher  and  Lohmann  4  have  found  neurin  in  human 
urine.  It  seems  possible  that  some  of  the  toxic  effects  observed 
after  eating  excessively  of  such  foods  as  calves7  brains,  or  eggs, 
may  depend  upon  intoxication  with  the  products  of  lecithin 
decomposition. 

RESULTS  OF  GASTRO-INTESTINAL  INTOXICATION 

As  we  have  seen  from  the  above,  but  few  of  the  known 
products  of  gastro-intestinal  putrefaction  are  toxic  to  any  con- 
siderable degree,  and  these  are  probably  produced  in  too  small 
quantities  to  cause  any  appreciable  effect,  especially  in  view  of 
the  detoxicating  and  eliminatory  powers  of  the  liver,  kidney, 
and  other  organs.  And  yet  we  have  abundant  clinical  evidence 
that  excessive  intestinal  putrefaction  or  retention  of  the  intesti- 
nal contents  cause  marked  disturbance  in  health.  The  slight 
malaise,  headache,  and  lassitude  observed  as  the  result  of  simple 
constipation  may  possibly  be  adequately  accounted  for  by 

1  Meyer  and  Langstein,  Jahrb.  f.  Kinderheilk.,  1906  (63),  30. 

2  Literature  given  by  Halliburton,  Ergebnisse  der  Physiol.,  1904  (4),  24. 

?  Jour.  Exp.  Med.,  1899  (4),  1 ;  see  also  Hoesslin,  Hofmeister's  Beitr.,  1906 
(8),  27. 

4  Zeit.  physiol.  Chem.,  1906  (48),  1. 


RESULTS  OF  G ASTRO-INTESTINAL  INTOXICATION   481 

intoxication  with  indol  and  similar  substances,  although  we 
have  no  conclusive  proof  that  such  is  the  case.  But  the  violent 
effects  that  follow  complete  occlusion  of  the  intestine,  especially  in 
the  upper  portion,  must  be  due  to  some  highly  toxic  substance 
or  substances.  The  clinical  features  of  obstructive  ileus, 
namely,  vomiting,  collapse,  complete  muscular  relaxation,  and 
subnormal  temperature,  are  associated  with  the  excretion  of 
large  quantities  of  indican  and  other  substances  combined  with 
sulphuric  acid,  proving  that  intestinal  putrefaction  is  active. 
Undoubtedly  in  ileus  we  have  a  profound  and  rapidly  fatal 
intoxication  with  substances  formed  in  the  obstructed  intestines, 
but  as  yet  we  have  not  isolated  any  substances  from  the 
alimentary  canal  that  possess  sufficient  toxicity  to  account  for 
such  an  intoxication,  except  possibly  the  derivatives  of  cholin, 
and  these  are  probably  formed  in  too  small  amounts  to  account  for 
the  conditions  observed.  Two  explanations  may  be  suggested : 
One  is  that  the  intestinal  flora  becomes  altered  because  of  the 
changed  conditions,  and  bacteria  thrive  that  produce  specific 
soluble  toxic  substances,  analogous  to  those  formed  by  B.  botu- 
linus,  or  similar  to  the  tyrotoxicon  (Vaughan)  that  may  be 
formed  in  milk  and  milk  products.  Thus  Clairmont  and 
Ranzi l  found  heat-resistant  toxic  substances  in  the  intestinal  con- 
tents in  ileus  (experimental),  and  similar  substances  could  also 
be  obtained  by  growing  cultures  of  the  intestinal  contents  on 
bouillon.  Another  explanation  is  that  many  unidentified  poison- 
ous substances  are  produced  in  the  alimentary  canal  which 
ordinarily  are  destroyed,  but  under  certain  conditions  may  be 
reabsorbed.  That  unrecognized  toxic  substances  are  formed  in 
the  intestines  is  almost  certain,  for  it  has  been  repeatedly 
shown  that  extracts  of  the  contents  of  the  alimentary  canal  are 
very  poisonous.  Although  the  technic  of  many  of  these  experi- 
ments has  been  questionable,  the  results  have  so  often  been 
obtained  as  to  render  it  probable  that  the  main  contention  is 
correct.2  Thus  Magnus- Alsleben 3  has  found  in  the  upper  part 
of  the  small  intestine  of  dogs  (except  when  on  milk  diet)  a 
very  poisonous  substance  which  kills  rabbits  by  respiratory 
paralysis,  but  which  is  inert  when  injected  into  the  portal  vein. 
In  any  case,  correctly  or  incorrectly,  a  great  number  of  disease 
conditions  have  been  attributed  to  poisons  of  gastro-intestinal 
origin,  including  not  only  such  minor  conditions  as  headache, 

1  Arch.  klin.  Chir.,  1904  (73),  696. 

2  For  example,  see  Koger  and  Gamier,  Compt.  Kend.  Soc.  Biol.,  1905  (59), 
388  and  674  ;  1906  (60),  666. 

3  Hofmeister's  Beitr.,  1905  (6),  503. 

31 


482       GASTRO-INTESTINAL  "AUTOINTOXICATION" 

malaise,  lassitude,  etc.,  but  also  sciatica,  tetany,  epilepsy, 
eclampsia,  many  forms  of  dermatitis,  various  forms  of  nervous 
diseases,  myxedema  and  cretinism,  chlorosis  and  pernicious 
anemia,  cirrhosis,  nephritis,  and  arteriosclerosis.1  While  in 
many  cases  the  severity  of  these  various  conditions  is  apparently 
augmented  by  intestinal  disturbances,  the  etiologic  relation  is 
not  so  clear.  That  long-continued  intoxication  of  intestinal 
origin  may  cause  serious  injury  to  the  tissues  is,  however, 
extremely  probable.  There  is  much  reason  for  believing  that 
many  cases  of  non-alcoholic  cirrhosis  are  due  to  this  cause ; 
not  improbably  chronic  nephritis,  myocarditis,  and  arterio- 
sclerosis may  occasionally  be  the  result  of  long-continued 
intoxication  from  the  same  source. 

Tetany  associated  with  gastric  dilatation  offers  perhaps  the 
strongest  case,  numerous  observers  having  reported  finding  a 
marked  toxicity  of  the  stomach  contents.2  Pineles 3  considers 
that  all  forms  of  tetany,  whether  of  gastric  origin  or  following 
thyroidectomy,  are  due  to  one  and  the  same  "tetany  poison." 

The  relation  of  intestinal  intoxication  to  the  various  anemias, 
particularly  chlorosis  and  pernicious  anemia,  has  been  repeat- 
edly indicated  and  discussed.  Clinical  evidence  strongly 
indicates  that  such  a  relation  exists,  and  there  is  no  doubt  that 
hemolytic  substances  may  be  formed  in  the  alimentary  tract,4 
but  that  chlorosis  and  pernicious  anemia  do  depend  upon  in- 
testinal putrefaction  or  infection  is  far  from  established  (see 
"Anemia,"  Chap.  xi). 

It  seems  highly  probable  that  gastro-intestinal  "  autointoxica- 
tion "  would  be  a  much  more  serious  matter  were  it  not  for  the 
mechanisms  of  defence  possessed  by  the  body,  especially  in  the 
liver.5  For  example,  Richards  and  Howland  have  indicated 
the  increased  toxicity  of  indol  when  the  oxidizing  power  of  the 
liver  is  reduced,  and  Herter  and  Wakeman  have  shown  the 
power  of  the  liver  to  combine  indol  and  thus  remove  it  from 
circulation.  This  topic  has  been  discussed  more  fully  elsewhere 
(Chap.  vii). 

1  The  relation  of  gastro-intestinal  intoxication  to  these  various  diseases  is 
reviewed  by  Weintraud,  Ergeb.  allg.  Pathol.,  1897  (4),  17. 

2  Bibliography  by  Halliburton  and  McKendrick,  Brit.  Med.  Jour.,  1901  (i ), 
1607. 

3  Deut.  Arch.  klin.  Med.,  1906  (85),  491. 

4  See  Kiilbs,  Arch,  exper.  Path.,  1906  (55),  73;  also  Herter,  Jour.  BioL 
Chem.,  1906  (2),  1. 

5  For  discussion  and  literature  see  Lust,  Hofmeister's  Beitr.,  1905  (6),  132. 


CHAPTER    XX 

CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS 
GLANDS 

DISEASES  OF  THE  THYROID1 

As  we  have  much  evidence  that  the  thyroid  has  a  marked 
influence  upon  metabolism,  and  also  that  it  may  be  of  impor- 
tance in  preventing  autointoxication,  the  chemistry  of  diseases 
of  the  thyroid  may  be  appropriately  considered  in  connection 
with  the  autointoxications. 

THE  FUNCTIONS  OF  THE  THYROID 

Metabolic  Function. — That  the  thyroid  has  an  important 
relation  to  metabolism,  especially  of  proteids,  is  shown  by  the 
following  facts  : 

(1)  Administration  of  the  gland  substance,  or  active  prepara- 
tions made  from  it,  to  healthy  men  or  animals,  causes  a  greatly 
increased  elimination  of  nitrogen  in  the  form  of  urea.    This  nitro- 
gen comes  not  only  from   the  food,  but  also  from  increased 
tissue-destruction,  as  is  shown  by  the  loss  of  weight  and  strength. 
An  increased  destruction  of  the  body  fat  also  occurs,  so  that 
thyroid  therapy  has  been   found  efficient  in  the  treatment  of 
obesity,  but  often  dangerous   because  of  the    relatively  great 
amount  of  tissue-destruction.2 

(2)  Loss  of  thyroid  tissue,  either  through  operation  or  dis- 
ease, greatly  reduces  both  nitrogenous  metabolism  and  oxida- 
tive  processes.     Administration  of  thyroid  preparations  under 
these  conditions  will  bring  the  nitrogen  elimination  and  the  gas 
exchange  back  to  normal. 

(3)  Deficient  thyroid    secretion  in  young  animals  prevents 
their  developing  normally,  the  amount  of  deficiency  varying 
from  nearly  total  lack  of  development  in  extreme  cretinism  to 
slight  grades  of  defective  development  (infantilism)  or  delayed 

1  General  literature  given  by   Shaw,    "Organotherapy,"    London,  1905; 
Richardson,   "The   Thyroid   and   Parathyroid   Glands,"  Philadelphia,  1905. 
For  earlier  literature  see  Mobius,  Nothnagel's  System,  vol.  22  ;  Wells.   Jour. 
Amer.  Med.  Assoc.,  1897  (29),  897. 

2  See  Rheinboldt,  Zeit.  klin.  Med.,  1906  (58),  425. 

483 


484   CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS  GLANDS 

maturity.1  In  adult  animals,  besides  decreased  metabolism 
there  occur  also  various  trophic  changes  in  the  skin  and  its 
appendages,  an  increased  amount  of  mucin-like  material  in  the 
tissues,  and  greatly  decreased  nervous  and  mental  activity. 
All  these  conditions  are  relieved  to  greater  or  less  degree  by 
administration  of  thyroid  tissue  or  its  preparations.  Evidently, 
therefore,  the  thyroid  exerts  an  influence  upon  growth  and  tis- 
sue changes ;  whether  this  depends  upon  its  influence  upon 
metabolism,  or  is  an  independent  and  specific  function,  cannot 
be  determined. 

How  the  thyroid  or  its  secretion  modifies  metabolism  is  not 
yet  understood.  One  is  reminded  of  the  effects  of  kinases  upon 
enzymes  and  their  antecedents,  and  it  may  be  imagined  that  the 
thyroid  secretion  activates  both  proteolytic  and  oxidative 
enzymes  within  the  cells.  Shryver,2  indeed,  did  find  that 
administration  of  thyroid  to  dogs  for  some  time  before  killing 
them  causes  their  liver  tissue  to  undergo  autolysis  more  rapidly 
than  normal,  although  Wells3  had  been  unable  to  observe 
any  increased  amount  of  autolysis  when  thyroid  extracts  acted 
upon  liver  tissue  in  vitro. 

Detoxicatory  Function. — The  evidence  that  the  thyroid 
has  for  its  function  the  destruction  or  neutralization  of  poisonous 
substances  formed  in  metabolism  or  through  intestinal  putrefac- 
tion is  as  follows  : 

(1)  After  total  removal  of  the  thyroid  from  many  species  of 
animals  acute  symptoms  develop  that  suggest  strongly  an  intox- 
ication ;  often  a  typical  tetany  develops,  resembling  the  tetany 
that  is  associated  with  gastric  dilatation,4  and  which,  as  pre- 
viously mentioned,  is  believed  to  be  due  to  toxic  products  of 
gastric  putrefaction  and  fermentation. 

(2)  After  removal  of  the  thyroid,  marked  changes  occur  in  the 
blood,  there  being  a  severe  anemia  (as  low  as  2,000,000  red  cor- 
puscles),  with  some  leucocytosis,   and   there   occur  structural 
changes  in  the  blood-vessel  walls  (Kishi 5).    Cytoplasmic  degen- 
eration of  the  liver,  kidneys,  and  myocardium  may  also  result 
(Bensen 6).        These  effects   suggest  strongly    the   presence  of 
poisonous  substances  in  the  blood  of  persons  or  animals  lacking 
sufficient  thyroid  tissue. 

1  Literature  concerning  effect  of  thyroidectomy  upon  generative  functions 
riven  by  Caro,  Berl.  klin.  Woch.,  1905  (42),  310  ;  and  Lanz,  Beitr.  klin.  Chir., 
1905  (45),  208. 

2  Jour,  of  Physiol,  1905  (32),  159. 

3  Amer.  Jour.  Physiol.,  1904  (11),  351. 

4  See  Pineles,  Deut.  Arch.  klin.  Med.,  1906  (85),  491. 

5  Virchow's  Arch.,  1904  (176),  260. 

6  Virchow's  Arch.,  1902  (170),  229. 


THE  FUNCTIONS  OF  THE  THYROID  485 

(3)  All  the  effects  of  thyroidectomy  are  more  marked  in  car- 
nivorous animals  than  in  herbivora ;  indeed,  the  latter  may  be 
able  to  live  in  fair  condition  for  several  years  without  a  thyroid.1 
Administration  of  meat  to  thyroidectomized  herbivora  or  omniv- 
ora  causes  a  great  increase  in  the  symptoms,  while  thyroidec- 
tomized carnivora  do  much  better  if  kept  without  meat.  Thus, 
Blum 2  found  that  thyroidectomized  dogs,  which  were  doing  well 
on  a  milk  diet,  developed  symptoms  of  athyreosis  immediately 
they  were  given  meat.  This  fact  has  been  interpreted  as  indi- 
cating that  toxic  materials  are  formed  from  meat  in  the  intes- 
tinal tract,  which  under  normal  conditions  are  neutralized  by 
the  thyroid.  In  support  of  this  view  is  the  observation  of 
Watson  3  that  a  pure  meat  diet  causes  in  fowls  a  great  hyper- 
trophy of  both  the  thyroid  and  the  parathyroid  glands,  while  in 
rats  hyperplastic  changes  resembling  those  of  exophthalmic 
goiter  are  produced  by  meat  diet.  On  the  other  hand,  one  may 
well  imagine  that  the  so-called  autointoxication  in  athyreosis  is 
not  from  intestinal  putrefaction,  but  is  due  to  the  products  of 
incomplete  metabolism  of  proteids  within  the  tissues,  which  are 
destroyed  when  proteid  metabolism  is  normal,  but  not  when  the 
metabolism-favoring  influence  of  the  thyroid  is  wanting.  It 
should  also  be  added  that  the  presence  of  specific  poisonous 
substances  in  the  blood  or  urine  of  thyroidectomized  animals 
has  not  been  conclusively  established.4 

Relation  to  Generative  Functions. — The  hypertrophy 
of  the  thyroid  that  occurs  at  puberty,  during  menstruation,  and 
especially  during  lactation,  is  possibly  in  response  to  an  auto- 
intoxication, but  far  more  probably  in  response  to  the  increased 
proteid  metabolism.  In  pregnancy  and  lactation  the  maternal 
thyroid  functionates  for  both  mother  and  offspring,  the  thyroid 
of  the  new-born  containing  either  no  iodin  at  all  or  but  the  most 
minute  traces.  If  the  greater  part  of  the  thyroid  is  removed 
from  pregnant  bitches,  the  puppies  show  a  great  compensatory 
hypertrophy  of  the  thyroid  (Halsted  5). 

1  Part  of  these  results  may  be  due  to  the  fact  that  in  some  herbivora  the 
parathyroids  are  so  far  separated  from  the  thyroid  that  they  are  not  ordinarily 
removed  in  thyroidectomy,  whereas  in  many  carnivora  complete  removal  of 
parathyroids  with  the  thyroids  is  more  likely  to  be  accomplished. 

2  Virchow's  Arch.,  1900  (162),  375. 

3  Lancet,  1905  (i),  347. 

*Kemedi  (Lo  Sperimentale,  1902;  abst.  in  Cent.  f.  Path.,  1903  (14),  695) 
claims  that  tetanus  toxin  and  other  bacterial  poisons,  when  injected  into  the 
thyroid  gland,  are  harmless,  which  he  attributes  to  a  neutralization  by  the 
colloid. 

5  Johns  Hopkins  Hosp.  Rep.,  1896  (1),  373  ;  also  Edmunds,  Trans.  London 
Path.  Soc.,  1900  (51),  221. 


486   CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS  GLANDS 


CHEMISTRY  OF  THE  THYROID 

Whether  the  function  of  the  thyroid  is  the  neutralization  of 
toxic  substances,  or  a  complementary  action  upon  intracellular 
metabolism,  there  can  be  little  question  that  it  owes  its  action  to 
constituents  of  its  specific  secretion,  the  colloid.  Furthermore, 
the  chief,  if  not  the  sole,  active  ingredient  of  the  colloid  is  the 
iodin-containing  substance  first  discovered  by  Baumann  in  1896, 
and  called  by  him  thyroiodin  (or  iodothyrein). 

The  chemical  nature  of  thyroid  colloid  has  been  studied 
particularly  by  Oswald.1  He  found  that  all  the  iodin  of  the 
thyroid  is  dissolved  out  in  physiological  salt  solution,  and  that 
none  of  it  is  present  in  an  inorganic  form.  In  the  salt  solution 
extract  are  two  proteid  bodies :  one,  precipitated  by  half  satura- 
tion with  ammonium  sulphate,  contains  all  the  iodin,  and  seems 
to  be  a  globulin  ;  it  resembles  myosin  in  being  precipitated  by 
weak  acids,  and  it  contains  an  easily  separated  carbohydrate 
group.  The  other,  precipitated  by  saturation  with  ammonium 
sulphate  (exact  limits  of  precipitation  are  between  6.4  and  8.2 
tenths  saturation),  is  a  nucleoproteid,  containing  0.16  per  cent, 
phosphorus,  but  no  iodin. 

The  iodin-containing  proteid,  called  thyreoglobulin,  seems  to 
be  the  sole  active  constituent  of  the  colloid  ;  at  least,  its  admin- 
istration to  animals  has  the  same  physiological  effects  as  does 
the  entire  colloid  (great  increase  in  the  urea  elimination  and 
decrease  in  blood  pressure  in  animals,  curative  effect  on  myx- 
edematous  patients),  whereas  the  nucleoproteid  is  without  these 
effects.  Analysis  of  the  thyreoglobulin  from  various  animals 
has  shown  it  to  be  of  quite  constant  quantitative  composition 
except  for  the  iodin,  which  may  vary  greatly  in  amount.  Nor- 
mal human  thyreoglobulin  (from  persons  living  in  non-goitrous 
districts)  had  the  following  percentage  composition  : 
0  =  51.85,  H  =  6.88,  N  =  15.49,  1  =  0.34,  S  =  1.86. 

Thyreoglobulin  from  goitrous  districts  contains  much  less  iodin 
(0.18-0.19  per  cent.),  and  from  calves  born  with  goiters  a  thy- 
reoglobulin was  obtained  that  agreed  in  all  respects  with  normal 
thyreoglobulin,  except  that  it  contained  no  iodin  at  all.  On  the 
other  hand,  administration  of  iodides  to  patients  causes  the  thy- 
reoglobulin to  become  rich  in  organically  bound  iodin.2  From 

1  His  work  is  reviewed  in  his  dissertation,  "  Die  chem.  Beschaffenheit  und 
die  Function  der  Schildruse  "  Strassburg,  1900 ;  also  see  Virchow's  Arch.,  1902 
(169),  444. 

2Nagel  and  Roos  (Arch.  f.  Anat.  u.  Physiol.,  1902,  p.  267)  found  that 
administration  of  bromides  had  no  effect  upon  the  amount  of  iodin  in  the  thy- 
roid, and  no  storage  of  bromin  takes  place.  Administration  of  pilocarpine 


THE  PARATHYROIDS  487 

these  facts  Oswald  believes  that  the  thyreoglobulin,  as  first 
secreted  by  the  glandular  epithelium,  is  free  from  iodin,  and  that  it 
combines  later  with  iodin  from  the  circulating  blood.  As  yet  it 
has  not  been  ascertained  how  the  iodin  is  bound  to  the  proteid. 
It  is  well  known  that  large  amounts  of  iodin  can  be  introduced 
into  the  proteid  molecule,  apparently  through  its  substitution  for 
hydrogen  in  the  aromatic  radicals  (tyrosin,  phenylalanin,  etc.). 
Thyreoglobulin  is  not,  however,  simply  an  iodized  proteid,  for 
the  iodized  proteid s  that  can  be  artificially  prepared  do  not  pos- 
sess the  physiological  activity  of  the  thyreoglobulin ;  further- 
more, the  saturated  iodized  proteids  contain  generally  from  5  to 
12  per  cent,  of  iodin,  as  contrasted  with  the  0.3  to  0.8  per 
cent,  of  thyreoglobulin.  Oswald  has  shown  that  in  thyreoglob- 
ulin the  iodin  is  not  bound  to  tyrosin,  since  this  can  be 
removed  by  tryptic  digestion  without  decreasing  the  amount  of 
iodin  in  the  rest  of  the  molecule ;  possibly  the  iodin  is  bound  to 
phenylalanin. 

By  decomposing  thyreoglobulin  by  boiling  with  10  per  cent, 
sulphuric  acid,  a  body  is  obtained  containing  as  high  as  14.5  per 
cent,  of  iodin ;  this  is  the  thyroiodin  of  Baumann,  which  gives 
no  biuret  reaction,  yet  is  physiologically  active.  The  stability 
of  this  active  constituent  of  the  thyreoglobulin  explains  the 
successful  administration  of  thyroid  preparations  by  mouth.  It 
appears  to  be  absorbed  unchanged  and,  unless  enormous  doses 
are  given,  none  appears  in  the  urine  (Oswald). 

The  amount  of  iodin  in  the  thyroid  is  greatest  in  middle  age, 
greater  in  females  than  in  males,  and  it  is  decreased  in  acute 
infectious  diseases  and  in  tuberculosis,  alcoholism,  and  circula- 
tory disturbances  (Aeschbacher  *). 

THE  PARATHYROIDS 

Whether  the  thyroid  has  any  other  function  than  the  forma- 
tion of  thyroiodin  is  as  yet  unknown.  Many  claim  that  the 
thyreoglobulin  does  not  produce  the  same  physiologic  and  thera- 
peutic effects  as  does  the  entire  gland  substance,  but  even  that 
is  not  definitely  decided.  Furthermore,  it  is  difficult  to  distin- 
guish between  the  effects  produced  by  the  parathyroid  glands 
and  those  due  to  the  thyroid  itself.  The  parathyroids  were 
originally  considered  as  but  a  form  of  undeveloped  accessory 

does  not  increase  the  amount  of  iodin  in  the  thyroid.  Coronedi  and  Mar- 
chetti  (Bivista  di  Patologia,  1902)  consider  that  administration  of  fatty  com- 
binations of  iodin  and  bromin  may  partially  compensate  for  loss  of  the  thy- 
roid. 

1  Mitt.  a.  d.  Grenzgeb.  med.  u.  Chir.,  1905  (15),  269. 


488   CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS  G LANDS 

thyroids  (a  view  still  held  by  some l),  but  they  are  now  gener- 
ally believed  to  be  independent  organs  of  fully  as  great  impor- 
tance as  the  thyroid.  To  their  removal  are  ascribed  by  many 
investigators  the  acute  manifestations  of  athyreosis,  while  the 
more  chronic  changes  of  myxedema  are  attributed  to  the  loss  of 
the  thyroid.2 

MacCallum's  studies  support  this  view,  for  he  found  the 
results  of  parathyroidectomy  in  dogs  very  different  from  the 
results  of  thyroidectomy.  The  most  prominent  symptoms  were 
muscular  twitchings,  gradually  passing  into  tetanic  spasms,  and 
due  to  nervous  impulse  rather  than  to  muscular  changes,  since 
they  did  not  appear  in  muscles  from  which  the  nerve-supply  had 
been  cut  off.  Trismus,  protrusion  of  the  eyes,  and  rapid 
respiration  without  cyanosis  (i.  e.,  air  hunger)  were  also 
observed,  and  death  usually  resulted  from  exhaustion.  Appar- 
ently these  symptoms  are  due  to  some  toxic  substance  which 
accumulates  on  account  of  the  absence  of  the  parathyroids,  for  it 
was  found  that  simply  diluting  the  dog's  blood  by  withdrawing 
part  of  it,  and  injecting  a  corresponding  amount  of  salt  solu- 
tion, caused  a  temporary  cessation  of  the  tetanic  symptoms ; 
and  injections  of  emulsions  of  parathyroid  checked  the  symp- 
toms for  some  time,  presumably  through  neutralizing  the  hypo- 
thetical poisons.  Degenerative  changes  that  were  observed  in 
the  cerebral  ganglion-cells  also  favor  the  view  that  some  unneu- 
tralized  toxin  is  responsible  for  the  symptoms  following  para- 
thyroidectomy. Of  particular  importance  is  the  demonstra- 
tion by  MacCallum  and  Slemons  that  parathyroidectomy  has 
practically  no  effect  upon  proteid  metabolism,  in  marked  con- 
trast to  the  effect  of  thyroidectomy. 

CHEMISTRY  OF  GOITER 

In  connection  with  his  earliest  studies  of  thyroiodin,  Bau- 
mann  observed  a  great  difference  in  the  amount  of  iodin  in 
the  thyroid  glands  of  normal  individuals  living  in  goitrous  dis- 
tricts, as  compared  with  those  living  in  non-goitrous  districts. 
Thus  in  Freiburg,  a  goitrous  district,  the  average  weight  of  the 
dried  thyroid  was  8.2  grams,  each  gram  containing  0.33  mg. 
of  iodin,  a  total  of  2.5  mg.  of  iodin  to  each  gland.  Glands 
from  Hamburg  averaged  4.6  gm.  in  weight,  containing  0.83  mg. 
of  iodin  per  gram,  a  total  of  3.83  mg.  per  gland.  Berlin 
glands  weighed  7.4  grams,  and  contained  0.9  mg.  of  iodin 

1  Kishi,  Virchow's  Arch.,  1904  (176),  260. 

2  Full  discussion  by  Kichardson,  "  The  Thyroid  and  Parathyroid  Glands," 
Philadelphia,  1905,  pp.  29-40;  and  MacCallmn,  Med.  News,  1903  (83),  820. 


CHEMISTRY  OF  GOITER  489 

per  gram,  or  a  total  of  6.6  mg.  of  iodin  per  gland.  Both 
of  the  last-named  cities  are  in  districts  where  goiter  is  not 
endemic.  The  thyroids  of  young  children  show  the  same 
relative  paucity  of  iodin  in  goitrous  districts,  as  compared 
with  non-goitrous  districts.  Wells1  found  that  the  thyroids 
throughout  the  United  States  contain  even  larger  amounts  of 
iodin  than  the  Berlin  glands,  averaging  10  to  12  mg.  per  gland, 
agreeing  with  the  fact  that  goiter  is  comparatively  rare  in  this 
country.2  Monery3  has  found  for  France,  as  Baumann  did 
for  Germany,  that  the  amount  of  iodin  contained  in  the  glands 
of  normal  individuals  is  in  inverse  proportion  to  the  frequency 
of  goiter  in  districts  in  which  they  live.  Oswald,  and  also 
Aeschbacher,4  however,  state  that  normal  thyroids  in  goitrous  dis- 
tricts contain  more  iodin  than  thyroids  from  goiter-free  districts. 
Chemical  analyses  of  goiters  have  given  extremely  variable 
results,  and  as  yet  have  not  led  to  any  satisfactory  explanation 
of  the  etiology  of  this  condition.  Baumann  found  that  in  a 
series  of  twelve  cases  of  goiter,  in  which  the  average  dry 
weight  was  32  grams,  the  amount  of  iodin  in  each  gram  was 
but  0.09  mg.,  but  the  total  amount,  2.6  mg.,  was  about  the 
same  as  in  normal  glands  of  the  same  goitrous  district.  How- 
ever, in  two  goiters  large  amounts  of  iodin  were  found,  namely, 
17.5  mg.  and  31.5  mg.  Wells  found  that  the  amount  of  iodin 
depended  upon  the  structure,  for  two  hyperplastic  goiters  con- 
tained respectively  8.23  and  8.3  mg.  of  iodin,  or  about  the 
amount  normal  for  thyroids  in  this  country,  whereas  two  colloid 
goiters  contained  53.16  and  24.59  mg.  of  iodin.  In  an  adeno- 
matous  goiter  the  new-growth  was  found  to  contain  1.98  mg. 
of  iodin  per  gram,  while  the  rest  of  the  gland  contained  but 
0.8  mg. ;  the  total  amount  of  iodin  was  9.26  mg.,  or  the  same 
quantity  as  found  in  normal  glands.  It  would  seem  that  in 
some  cases  of  goiter  hyperplastic  changes  are  required  to  bring 
the  amount  of  iodiu  up  to  normal,  perhaps  because  of  a  scarcity 
of  iodin  in  the  food  or  a  defective  assimilation.  In  support  of 
this  is  the  fact  that  Bruns  found  that  hyperplastic  goiters  are  the 
form  most  successfully  treated  by  administration  of  thyroiodin. 
Colloid  goiters  possibly  depend  upon  a  deficiency  in  absorption 
of  the  colloid  from  the  follicles,  or  possibly  upon  a  reduced 
utilization  of  the  thyroid  secretion  by  the  body,  although  we 
have  no  evidence  for  this. 

1  Jour.  Amer.  Med.  Assoc.,  1897  (29),  897. 

2  It  is  probable,  in  view  of  the  higher  results  obtained  by  Wells  and  by 
Oswald,  that  the  results  of  Baumann  and  of  Monery  are  somewhat  too  low. 

3  Jour.  Pharm.  et  Chim.,  1904  (95),  288. 

4  Mitt.  a.  d.  Grenzgeb.  Med.  u.  Chir.,  1905  (15),  269. 


490   CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS  GLANDS 

Oswald  obtained  different  results  through  analyses  of  the 
colloid  of  colloid  goiters,  finding  that  colloid  goiters  contain  a 
thyreoglobulin  that  is  relatively  very  poor  in  iodin ;  in  goitrous 
calves  the  thyreoglobulin  contained  no  iodin  ;  in  human  goiters 
it  contained  but  0.07  to  0.19  per  cent,  of  iodin,  as  against  a 
normal  proportion  of  0.34  per  cent.  Administration  of  iodides 
to  a  goitrous  patient  caused  a  rise  in  the  proportion  of  iodin  in 
the  colloid  to  0.51  per  cent.,  showing  that  in  colloid  goiters  in 
goitrous  districts  the  thyreoglobulin  is  probably  poor  in  iodin 
because  of  a  lack  of  iodin  for  it  to  unite  with,  and  not  because 
it  is  of  an  abnormal  nature  that  prevents  its  chemical  combina- 
tion with  iodin.1  Possibly  this  explains  the  greater  iodin  con- 
tent observed  in  colloid  goiters  in  the  United  States  as  compared 
with  colloid  goiters  observed  in  goitrous  districts.  In  general, 
Oswald 2  found  the  amount  of  iodin  to  vary  with  the  amount 
of  colloid  in  the  goiters,  although  occasionally  goiters  with 
exceptionally  large  amounts  of  iodin  were  found,  and  the  pro- 
portion of  iodin  is  not  usually  so  great  when  the  amount  of 
colloid  is  very  large.  Simple  hyperplastic  goiters  he  found 
poor  in  iodin,  or  free  from  it  if  they  contained  no  colloid  ; 
however,  they  were  found  to  contain  a  thyreoglobulin  typical 
in  all  respects  except  an  absence  of  iodin.  Presumably  in  such 
goiters  the  little  thyroiodin  present  is  contained  in  the  paren- 
chymatous  cells.  The  physiological  activity  of  thyreoglobulin 
obtained  from  goiters  was  found  to  be  the  same  as  that  from 
normal  glands,  except  that  it  was  weaker  in  direct  proportion 
to  the  amount  of  iodin  it  contained,  and,  therefore,  when  iodin- 
free  it  was  without  effect.  In  colloid  goiters  the  greater  part 
of  the  weight  of  the  gland,  three-fourths  or  more,  is  made  up 
of  this  colloid-poor  thyreoglobulin.  The  fluid  contents  of 
cystic  goiters  may  be  free  from  iodin,  but  if  they  contain  much 
colloid,  iodin  will  be  found,  and  Rositzky3  found  193  mg.  of 
iodin  in  20  c.c.  of  the  jelly-like  contents  of  a  thyroid  cyst. 

It  has  been  frequently  suggested  that  the  cause  of  endemic 
goiter  is  a  deficiency  in  the  iodin  in  the  food,  or  in  the  drink- 
ing-water, or  in  the  air  of  the  goitrous  district.  This  is  sup- 
ported by  the  relative  infrequency  of  endemic  goiter  in  districts 
on  the  sea-coasts,  where  the  iodin-containing  sea-water  is  sprayed 
through  the  air,  and  where  the  inhabitants  eat  largely  of  sea- 
foods. However,  there  are  many  exceptions,  and  it  cannot  be 
said  that  this  hypothesis  of  the  etiology  of  goiter  rests  on 

1  See  Kocher,  Mitt.  a.  d.  Grenzgeb.  Med.  u.  Chir.,  1905,  vol.  14. 
'VirchoVs  Arch.,  1902  (169),  444. 
8  Wien.  klin.  Woch.,  1897  (10),  823. 


MYXEDEMA  AND  CRETINISM  491 

satisfactory  evidence,  particularly  in  view  of  the  abundant 
iodin  content  of  many  goiters.  Epidemics  of  goiter  presum- 
ably are  the  results  of  an  infection  with  some  unknown  organ- 
ism, and  possibly  the  endemic  form  has  a  similar  cause.  There 
is  much  evidence,  in  any  event,  that  whatever  the  cause  of 
goiter  may  be,  it  often  is  related  to  the  drinking-water.1  Very 
probably  the  causes  of  colloid  goiter  and  parenchymatous  goiter 
will  be  found  to  be  different  from  each  other  and  from  the 
causes  of  cystic  and  adenomatous  goiters. 

MYXEDEMA  AND  CRETINISM 

These  conditions  depend  upon  a  deficiency  of  thyroid  secretion, 
whether  from  operative  procedure  or  from  pathological  altera- 
tions in  the  organ.  Consequently  we  find  evidences  of  a 
decreased  proteid  metabolism,  the  urine  containing  a  diminished 
quantity  of  nitrogen,  especially  in  the  form  of  urea,  while 
ammonia  and  other  forms  of  nitrogen  are  relatively  excessive. 
The  temperature  is  usually  subnormal.  Fat  and  carbohydrate 
metabolism  seem  not  to  be  proportionately  affected,2  and  hence 
the  elimination  of  CO2  is  relatively  high  as  compared  to 
the  nitrogen  elimination.  Gastro-intestinal  disturbances  are 
common,  with  resulting  increase  in  the  amount  of  indican  and 
ethereal  sulphates  in  the  urine.  Whether  from  this  cause  or 
from  deep-seated  metabolic  anomalies,  there  is  a  decided  anemia, 
and  the  ability  of  the  corpuscles  to  combine  with  oxygen  seems 
to  be  decreased,  so  that  the  arterial  blood  may  contain  less 
oxygen  than  normal  venous  blood.  It  is  impossible  to  say 
whether  the  failure  of  growth  and  development  of  the  young 
(cretinism),  and  the  mental  and  physical  torpidity  of  the  adult, 
are  due  to  an  autointoxication  from  products  of  intermediary 
metabolism  which  accumulate  because  of  the  failure  of  the 
thyroid  to  furnish  the  "  stimulus  "  necessary  for  their  complete 
destruction,  or  to  a  lack  of  some  essential  action  of  the  thyroid 
secretion  upon  the  nervous  tissues  and  the  growing  cells  them- 
selves. Administration  of  thyroid  extract  to  cretinoid  children 
causes  retention  of  nitrogen  and  phosphorus,  but  more  strikingly 
of  calcium.3 

The  myxedematous  change  in  the  connective  tissues  is  in 
the  nature  of  a  reversion  to  the  fetal  type  of  tissue,  and  sug- 
gests that  the  thyroid  secretion  is  necessary  for  proper  cell 

1  See  de  Quervain,  Mitt.  a.  d.  Grenzgeb.  Med.  u.  Chir.,  1905  (15),  297. 

2  Rarely   myxedema  and    diabetes    have    been   observed  conjointly   (see 
Strasser,  Jour.  Amer.  Med.  Assoc.,  1906  (44),  765). 

8  See  Hougardy  and  Langstein,  Zeit.  f.  Kinderheilk.,  1905  (61),  633. 


492   CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS  GLANDS 

growth.  This  effect  might  be  either  specific,  or  depend  simply 
on  the  effect  on  proteid  metabolism.  Horsley  l  describes  the 
appearance  of  the  tissues  of  animals  dying  after  thyroidectomy 
as  follows  :  The  subcutaneous  connective  tissue  is  swollen,  jelly- 
like,  bright  and  shining,  and  excessively  sticky.  The  same 
thing  is  observed  in  the  loose  tissue  of  the  mediastinum,  about 
the  heart,  and  in  the  omentum.  The  submaxillary  and  parotid 
glands  are  greatly  enlarged,  and  have  a  semi-translucent, 
swollen  appearance ;  from  the  cut  surface  a  sticky,  glairy  fluid 
exudes.  Apparently  the  parotid  becomes  transformed  into 
a  mucous  gland  ;  likewise  the  mucous  membrane  of  the  alimen- 
tary tract  is  swollen  and  transparent.  Fetal  tissues  contain 
normally  more  mucin  than  those  of  adults  (0.76  per  cent,  as 
against  0.37  per  cent,  in  the  subcutaneous  tissues,  according 
to  Halliburton),  and  in  the  early  stages  of  the  formation  of 
excessive  sub-cutaneous  tissue,  in  myxedema  such  an  increase 
of  mucin  may  be  present.  But,  under  ordinary  conditions, 
the  term  myxedema  seems  to  be  entirely  a  misnomer,  for 
Halliburton's  analyses  showed  that  the  skin  of  myxedematous 
patients  contains  quite  the  same  amount  of  mucin  as  is  present 
in  normal  skin.2  When  the  condition  is  of  long  standing,  the 
amount  of  mucin  may  even  be  much  reduced,  because  of  the 
development  of  a  fibroid  character  in  the  connective  tissue. 
However,  in  monkeys  upon  which  thyroidectomy  had  been 
performed,  Halliburton  3  found  a  decided  increase  in  the  mucin 
in  the  tissues  throughout  the  body,  especially  in  the  salivary 
glands,  but  also  in  the  skin,  subcutaneous  tissues,  and  tendons ; 
and  mucin  was  found  in  the  blood,  as  shown  by  the  following 
table : 


Skin  and 
subcutane- 
ous tissue. 

Tendon. 

Muscle. 

Parotid. 

Submax- 
illary. 

Blood. 

Normal  monkey  .    .    . 

0.89 

0.39 

0 

0 

«                 u 

0.9 

0.5 

0 

0 

o.i 

0 

After  thyroidectomy— 

55  days 

312 

255 

o 

072 

60 

035 

33  days  .... 

trace 

49  days 

2  3 

24 

1  7 

33 

08 

7  days    

0.45 

0.904 

0 

trace 

0.16 

trace 

'Brit.  Med.  Jour.,  1885  (i),  211. 

2  Jour,  of  Pathol.  and  Bact.,  1893  (1),  90. 

3  Quoted  by  Horsley,  loc.  cit. 


EXOPHTHALMIC  GOITER  493 

It  has  been  suggested  that  the  thyroid  produces  an  enzyme 
which  destroys  mucin,  but  that  such  is  the  case  has  never  been 
demonstrated.  Levin  1  states  that  mucin  is  toxic  for  thyroid- 
ectomized  rabbits,  but  this  is  not  substantiated  by  Nefedieff.2 

That  the  thyroid  is  connected  with  general  growth  is  shown 
not  only  by  the  thyroid  abnormalities  present  in  cretinism,  but 
also  by  the  frequent  observation  of  thyroid  defects  in  conditions 
of  delayed  growth  and  development  of  less  extreme  degree 
(infantilism),  and  the  favorable  effects  of  thyroid  feeding  in 
many  such  cases.  Also  in  certain  types  of  short-limbed  dwarfs 
(chondrodystrophia  fatalis)  some  thyroid  anomaly  may  have  an 
etiologic  bearing,  for  in  such  a  case,  in  which  the  thyroid  was 
histologically  greatly  altered  and  quite  free  from  colloid,  I  could 
find  no  trace  of  iodin.3  On  the  other  hand,  the  thyroid  of  a 
giant  which  I  have  analyzed  contained  62.9  mg.  of  iodin,  or 
six  times  the  amount  present  in  normal  glands.4 

EXOPHTHALMIC  GOITER 

It  has  by  no  means  been  conclusively  determined  that 
exophthalmic  goiter  is  due  to  an  intoxication  with  excessive 
amounts  of  thyroid  secretion,  either  normal  or  abnormal,  but 
there  is  abundant  evidence  in  favor  of  this  view.  Most 
important  is  the  similarity  of  exophthalmic  goiter  to  the  effects 
of  "  hyperthyroidism "  or  "  thyroidismus,"  produced  either 
experimentally  or  through  overuse  of  thyroid  extract  for  thera- 
peutic purposes.  In  thyroidismus  there  are  observed  a  rapid, 
weak  pulse ;  greatly  increased  metabolism,  especially  of  proteids  ;5 
increased  secretion,  especially  of  perspiration  ;  marked  nervous- 
ness and  irritability,  often  with  mental  confusion  and  delusions ; 
gastro-intestinal  disturbances,  especially  diarrhea ;  sweating, 
flushing,  tremors,  palpitation  of  the  heart,  loss  of  weight, 
and  slightly  increased  temperature  are  also  often  observed, 
and  not  rarely  typical  exophthalmos  may  appear.  These 
manifestations,  which  are  common  to  both  thyroidism  and  to 
exophthalmic  goiter,  are  quite  the  opposite  of  the  characteristic 
changes  of  myxedema,  with  its  general  lowering  of  all  metabolic 
and  nervous  processes.  Furthermore,  the  histological  changes 

1  Med.  Record,  1900  (57),  184. 

2  Vratch,  1901  (22),  Oct.  27. 

3  Reported  by  Hektoen,  Amer.  Jour.  Med.  Sci.,  1903  (125),  751. 

4  Reported  by  Bassoe,  Trans.  Chicago  Path.  Soc.,  1903  (5),  231. 

5  Metabolism  in  exophthalmic  goiter,  see :  F.  M tiller,  Deut.  Arch.  klin.  Med., 
1893  (51),  401  ;    Scholz,  Cent.  f.  inn.  Med.,  1895  (16),  1041;  Magnus-Levy, 
Berl.  klin.  Woch.,  1895  (32),  650 ;  Schondorff,  Pfluger's  Arch.,  1897  (67),  39o ; 
Voit,  Zeit.  f.  Biol.,  1897  (35),  116 ;  Clemens,  Zeit.  klin.  Med.,  1906,  Bd.  59. 


494  CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS  GLANDS 

observed  in  the  thyroid  are  usually  quite  the  same  as  those  of 
compensatory  hypertrophy,  suggesting  strongly  that  the  goitrous 
change  of  this  disease  is  due  to  a  true  hypertrophy,  with 
increased  production  of  the  specific  secretions.  Also  speaking 
strongly  in  favor  of  the  view  that  exophthalmic  goiter  is  the 
result  of  overactivity  of  the  thyroid  is  the  frequent  cure  of  the 
disease  through  removal  of  a  large  part  of  the  diseased  gland. 

Corroborative  evidence  of  the  hypersecretion  idea,  and  also 
of  the  theory  that  the  normal  function  of  the  thyroid  is  the  de- 
toxication  of  metabolic  products,  seems  to  have  been  furnished 
by  the  serum  treatment  advocated  first  by  Ballet  and  Enriquez, 
and  later  by  Lanz,  and  Burghart  and  Blumenthal.1  On  the 
principle  that  after  thyroidectomy  the  blood  should  contain  an 
accumulation  of  those  substances  which  the  thyroid  normally 
neutralizes,  they  injected  the  serum  of  thyroidectomized  goats 
into  patients  with  exophthalmic  goiter,  in  the  hope  that  these 
accumulated  substances  might  in  turn  neutralize  any  excessive 
thyroid  secretion.  Favorable  results  were  obtained,  and  it  was 
subsequently  found  that  the  milk  of  thyroidectomized  goats 
possesses  the  same  qualities,  and  may  be  administered  by  mouth  ; 
this  has  led  to  quite  extensive  clinical  use  of  this  method  of 
treatment,  which  at  the  time  of  writing  is  in  the  experimental 
stage.2  Of  similar  significance  are  the  favorable  effects  obtained 
by  Beebe 3  and  Rogers 4  with  a  serum  made  by  immunization  of 
animals  with  the  nucleoproteids  of  the  thyroid. 

Oswald 5  found  that  the  thyroid  in  exophthalmic  goiter  con- 
tains generally  a  smaller  proportion  of  iodin  than  normal  glands, 
but  with  the  total  amount  approximately  normal.  This  was  also 
the  result  of  two  analyses  that  I  have  made.  However,  the  find- 
ings are  very  inconstant,  corresponding  with  the  fact  that  in  some 
cases  of  exophthalmic  goiter  the  amount  of  colloid  is  abundant 
(in  which  case  the  amount  of  iodin  may  be  large),  while  usually 
the  amount  of  colloid  is  small,  and  its  highly  vacuolated  condi- 
tion in  hardened  sections  suggests  that  it  is  of  unusually  fluid 
consistency.  These  results,  therefore,  indicate  nothing  either 
for  or  against  the  hypothesis  that  exophthalmic  goiter  is  due  to 
autointoxication  with  the  secretion  of  the  thyroid. 

1  Deut.  med.  Woch.,  1899   (25),  627.      Also  Mobius,  Miincli.  med.  Woch. 
1901  (48),  1853 ;  v.  Leyden,  Med.  Klinik,  1904  (1),  1 ;  Eulenburg,  fieri,  klin. 
Woch.,  1905  (42),  3. 

2  Negative  testimony  as  to  the  value  of  this  treatment  given  by  Heinze, 
Deut.  med.  Woch.,  1906  (32),  755. 

3  Jour.  Amer.  Med.  Assoc.,  1906  (46),  484 ;  1906  (47),  655. 

4  Ibid.,  1906  (46),  487  ;  1906  (47),  661. 

5  Virchow's  Arch.,  1902  (169),  475. 


EXOPHTHALMIC  GOITER  495 

There  can  be  no  doubt  that  the  thyroid  secretion  is  capable 
of  causing  serious  intoxication,  for  patients  who  have  overused 
thyroid  preparations  in  the  treatment  of  obesity,  skin  diseases, 
etc.,  have  often  suffered  severely  from  the  symptoms  mentioned 
previously,  and,  in  at  least  one  such  case,  a  diagnosis  of  ex- 
ophthalmic goiter  was  made  before  the  cause  of  the  disturbance 
was  detected.  Not  infrequently  evidences  of  acute  intoxication, 
sometimes  resembling  tetany,  have  followed  immediately  after 
operations  upon  the  thyroid,  and  these  have  been  considered  as 
due  to  intoxication  with  the  large  quantities  of  thyroid  secretion 
that  have  escaped  from  the  gland  during  the  operative  manipu- 
lation. The  fact  that  amblyopia,  resembling  that  produced  by 
tobacco,  etc.,  may  follow  overuse  of  thyroid  preparations1  is 
also  indicative  of  their  toxicity,  as  also  is  the  glycosuria  that 
may  result  from  thyroid  administration. 

Even  if  the  hypothesis  that  exophthalmic  goiter  is  due  to  intox- 
ication with  thyroid  secretion  is  correct,  we  have  no  satisfactory 
explanation  of  the  cause  of  the  hyperactivity  of  the  thyroid.  In 
some  cases  degenerative  changes  have  been  observed  in  the 
superior  cervical  sympathetic  ganglia,  and  cure  or  improvement 
of  exophthalmic  goiter  is  said  to  have  followed  resection  of  these 
ganglia ;  however,  this  relation  has  not  been  observed  at  all 
constantly.  In  other  cases  there  has  been  evidence  that  sug- 
gested a  primary  intoxication  with  the  products  of  intestinal 
putrefaction,  leading  to  a  secondary  hyperplasia  of  the  thyroid, 
but  this  also  seems  to  be  an  exceptional  observation.  All  things 
considered,  it  seems  most  probable  that  the  hyperactivity  of  the 
thyroid  is  due  to  some  exciting  condition,  and  is  not  of  itself 
primary,  although  the  resulting  hyper  secretion  of  the  thyroid  may 
cause  the  dominant  features  of  the  disease.  The  frequent  associa- 
tion of  exophthalmic  goiter  with  puberty  and  pregnancy  suggests 
that  some  abnormality  in  the  function  of  the  generative  organs 
may  be  a  frequent  starting-point  of  the  thyroid  derangement. 

The  Relation  of  the  Parathyroids  to  Exophthalmic 
Goiter. — This  has  not  yet  been  definitely  established.  As 
nervous  manifestations  are  very  prominent  after  parathyroid- 
ectomy,  so  that  many  experimenters  attribute  all  the  acute 
nervous  and  muscular  symptoms  of  total  thyroidectomy  to 
simultaneous  removal  of  the  parathyroids,  it  has  seemed  very 
probable  that  these  organs  may  be  more  closely  associated  with 
exophthalmic  goiter  than  is  the  thyroid  itself.2  Against  the 

1  Birch-Hirschfeld  and  Inouye,  Graefe's  Arch.,  1905  (61),  499. 

2  This  subject  is  thoroughly  reviewed   by  MacCallum,  Med.  News,  1903 
(83),  820. 


496   CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS  GLANDS 

hypothesis  that  exophthalmic  goiter  is  due  to  parathyroid  in- 
sufficiency, however,  stand  the  following  facts  : 

(1)  Removal  of  one  lobe  of  the  thyroid  often  causes  im- 
provement or  recovery  in  this  disease,  yet  with  the  lobe  of  the 
thyroid  is  generally  removed  the  adjacent  parathyroid,  which 
would  decrease  the  amount  of  parathyroid  tissue,  and  make 
worse  any  existing  parathyroid  insufficiency.  (2)  Therapeutic 
administration  of  parathyroid  tissue  or  extract  has  had  no 
significant  effect  on  the  disease.  (3)  No  considerable  or 
characteristic  anatomical  changes  occur  in  the  parathyroids  in 
exophthalmic  goiter,1  while  the  great  majority  of  all  cases  show 
hypertrophic  changes  in  the  thyroid.  (4)  The  parathyroids 
seem  to  have  no  particular  influence  on  metabolism  (MacCal- 
lum),  while  metabolic  abnormalities  are  very  marked  in  exoph- 
thalmic goiter. 

ACROMEGALY  AND  THE  HYPOPHYSIS 
Although  in  nearly  all  cases  of  acromegaly  alterations  are 
observed  in  the  hypophysis,  yet  it  has  not  been  conclusively 
established  that  the  peculiar  overgrowth  characteristic  of  this 
disease,  and  of  giantism,  is  dependent  upon  this  organ.2  A 
great  variety  of  lesions  has  been  described  in  the  hypophysis  of 
acromegalics,  adenomatous  and  sarcoma-like  changes  having 
been  most  frequently  observed  ;  but  similar  and  equally  diverse 
lesions  have  been  observed  without  acromegaly.3  All  the  facts 
taken  together,  however,  point  to  hyperactivity  of  the  hypoph- 
ysis as  the  cause  of  acromegaly  :  in  some  cases  this  hyper- 
activity  is  associated  with  gross  enlargement,  but  often  the  gland 
shows  only  histological  changes,  which  consist  chiefly  of  hyper- 
plasia  of  the  chromophile  cells  of  the  anterior  lobe  (Lewis). 

Equally  contradictory  and  inconclusive  are  the  results  of  ex- 
perimental studies  of  the  normal  function  of  the  hypophysis, 
for,  while  some  observers  have  described  muscular  tremors  and 
spasms,  emaciation,  and  many  other  symptoms  after  extirpation 
of  the  hypophysis,  other  investigators  have  observed  no  effects  at 
all.4  Administration  of  hypophyseal  tissue  seems  to  have  no 
characteristic  effects  upon  either  metabolism  or  the  nervous 
system.  Thompson  and  Johnson 5  found  that  hypophysis  feed- 
ing causes  loss  of  weight  in  dogs  and  increased  elimination  of 
nitrogen  and  phosphoric  acid.  Extracts  of  the  anterior  lobe 

1  MacCallum,  Johns  Hopkins  Hosp.  Bull.,  1905  (16),  287. 

2  See  Mitchell  and  LeCount,  New  York  Med.  Jour.,  1899  (69),  517. 

3  Full  literature  given  by  Lewis,  Johns  Hopkins  Hosp.  Bull.,  1905  (16),  157. 

4  Friedmann,  Berl.  klin.  Woch.,  1902  (39),  436. 

5  Jour,  of  Physiol.,  1905  (33),  189. 


ACROMEGALY  AND  THE  HYPOPHYSIS  497 

cause  a  slight  fall  in  blood  pressure  (Hamburger *),  while  the 
infundibular  lobe  causes  some  rise  in  pressure  and  slowing  of 
the  heart  (Howell 2). 

That  the  hypophysis  is  related  to  the  thyroid  there  can  be  no 
question,  for  changes  in  one  organ  are  very  frequently  associ- 
ated with  changes  in  the  other.  Thus  Pel,3  Pope,4  and  others 
have  observed  the  association  of  myxedema  and  acromegaly ; 
thyroid  enlargement  is  almost  constantly  found  in  acromegaly 
and  giantism ;  in  exophthalmic  goiter  the  hypophysis  is  often 
histologically  changed  (Benda5).  In  some  cases  of  atrophy  of 
the  thyroid  an  increase  in  the  size  of  the  hypophysis  is  observed, 
which  resembles  a  compensatory  hypertrophy  in  that  a  consid- 
erable quantity  of  colloid-like  material  appears  in  the  gland ; 
this  has  been  described  in  myxedema  by  Ponfick,6  and  in  sclero- 
derma  by  Hektoen.7  Many  observers  state  that  after  thyroid- 
ectomy  a  similar  compensatory  hypertrophy  of  the  hypophysis 
occurs.  Furthermore,  the  normal  hypophysis  contains  iodin; 
in  fourteen  glands  that  I  collected  and  analyzed  the  total  amount 
of  iodin  was  0.05  mg.,  or  an  average  of  0.0036  mg.  for  each 
gland.8  The  proportion  of  iodin  is  about  one-fiftieth  as  much 
as  in  the  thyroid.  It  is  not  known  whether  the  iodin  is  con- 
tained in  the  form  of  thyreoglobulin  or  not,  but  the  fact  that 
the  hypophysis  may  contain  colloid,  and  that  it  is  embryologi- 
cally  of  similar  derivation  to  the  thyroid,  suggests  an  affirma- 
tive answer. 

Metabolism  in  Acromegaly. — Metabolism  has  been 
studied  in  a  few  cases  of  acromegaly,9  and  all  investigators  have 
observed  a  decided  retention  of  nitrogen  and  phosphorus,  corre- 
sponding to  the  growth  of  the  soft  tissue ;  and  a  less  marked 
retention  of  calcium,  because  of  overgrowth  of  bone ;  an 
unusually  large  proportion  of  the  calcium  seems  to  be  excreted 
by  the  kidneys  as  compared  to  the  bowels.  Excessive  excretion 
of  fatty  acids  without  acetone  was  observed  by  Edsall  and 

1  Amer.  Jour.  Physiol.,  1904  (11),  282. 

2  Jour.  Exp.  Med.,  1898  (3),  245. 

3  Berl.  klin.  Woch.,  1905  (42),  No.  44a,  p.  25. 

4  Brit.  Med.  Jour.,  1905  (ii),  1520. 

5  Arch.  Anat.  u.  Physiol.,  1900  (Physiol.  Abt),  373. 
6Zeit.  klin.  Med.,  1899  (38),  1. 

7  Cent.  f.  Path.,  1897   (8),  673.     According  to  the  studies  of  metabolism  in 
scleroderma  by  Bloch  and  Reitmann  (Wein.   klin.  Woch.,  1906  (19),  630) 
this  disease  bears  a  resemblance  to  thyroid  diseases,  rather  than  to  gastro- 
intestinal putrefaction,  as  has  been  suggested  frequently. 

8  Jour.  Amer.  Med.  Assoc.,  1897  (29),  1011. 

'Schiff,  Wien.  klin.  Woch.,  1897  (10),  277 ;  Moraczewski,  Zeitklin.  Med., 
1901  (43),  336;  Edsall  and  Miller,  Univ.  of  Penn.  Med.  Bull.,  1903  (16), 
143. 

32 


498   CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS  GLANDS 

Miller.  Franchini l  found  that  administration  of  hypophysis 
tablets  had  no  effect  upon  the  metabolism  of  an  acromegalic. 
Glycosuria  is  frequently  present  in  acromegaly,  and  is  also  often 
present  in  hypophyseal  tumors  without  acromegaly.2 

THE  ADRENALS  AND  ADDISON'S  DISEASE3 

In  common  with  the  other  ductless  glands,  the  adrenals  have 
been  considered  by  many  as  having  for  their  chief  function  the 
neutralization  of  poisons  of  metabolic  or  gastro-intestinal  origin. 
The  evidence  in  support  of  this  view  is,  however,  by  no  means 
conclusive.  When  the  function  of  the  adrenals  is  reduced 
through  pathological  alterations  (Addison's  disease),  or  abolished 
by  experimental  extirpation,  a  number  of  characteristic  consti- 
tutional changes  follow.  Most  prominent  is  the  profound  mus- 
cular weakness,  which  is  more  marked  by  early  fatigue  than  by 
weakness  during  a  single  effort.  The  decreased  cardiovascular 
tone  is  also  striking,  and  a  severe  anemia  is  usually  present. 
Gastro-intestinal  disturbance  is  marked,  anorexia,  nausea,  vom- 
iting, and  diarrhea  usually  occurring.  In  man,  pigmentation  of 
the  skin  and  mucous  membranes  with  a  pigment  resembling 
melanin  in  appearance,  is  one  of  the  most  striking  features,  and 
some  evidences  of  pigmentation  are  occasionally  observed  after 
experimental  adrenalectomy.  The  exact  nature  of  this  pig- 
ment, and  the  reasons  for  its  accumulation  in  Addison's  disease, 
are  both  unknown.  (Discussed  under  "  Pigmentation,"  page  397.) 
In  experimental  animals  it  has  been  found  that  the  blood  is 
toxic  for  other  animals,  which  is  usually  interpreted  as  meaning 
that  toxic  products  accumulate,  which  the  adrenals  normally  neu- 
tralize or  destroy ;  but  it  is  equally  possible  that  these  toxic 
substances  are  produced  only  after  removal  of  the  adrenals,  and 
not  in  normal  metabolism.4  The  metabolism  is  decreased,  but 
no  characteristic  changes  are  observed  (Neusser  5). 

Adrenalin. — Administration  of  adrenal  tissue  to  either 
man  or  animals,  while  unable  to  compensate  for  loss  of  the 
glands,  has  very  profound  effects.  These  are  due  chiefly,  if  not 

1  Bull.  sci.  med.  Bologna,  1905  (75),  8. 

2  Launois  and  Roy,  Arch.  G£n.  de  MeU,  1903  (191),  1102. 

3  General  review  and  literature  given  by  Shaw,  "  Organotherapy,"  London, 
1905. 

4  Sergent  (Presse  Med.,  1903  (11),  813)  describes  as  characteristic  of  "  acute 
insufficiency  of  the  adrenals"  a  certain  symptom-complex  that  simulates  a 
severe  intoxication.     Hemorrhage  into  the  adrenals  often  causes  acute  symp- 
toms resembling  a  profound  intoxication,  especially  like  peritonitis   (see  Sim- 
monds,  Virchow's  Arch.,  1902  (170),  242:  Dudgeon,  Amer.  Jour.  Med.  Sci., 
1904  (127),  134). 

5  Nothnagel's  System,  Bd.  xviii,  3  Teil. 


THE  ADRENALS  AND  ADDISON'S  DISEASE        499 

entirely,  to  the  presence  in  the  gland  of  a  specific  substance  with 
remarkably  great  power  of  raising  blood  pressure  by  causing 
general  arterial  contraction,  at  the  same  time  causing  contraction 
of  all  other  voluntary  muscles  that  are  under  control  of  the 
sympathetic  nervous  system.1  According  to  Langley 2  and  to 
Elliot,3  adrenal  extract  acts  upon  some  receptive  substance  pres- 
ent in  the  muscle,  which  is  independent  of  the  nervous  system, 
since  the  muscles  react  to  adrenalin  after  the  nerves  have  been 
sectioned  and  even  after  their  fibrils  and  endings  have  degenerated. 
Adrenal  administration  seems  to  have  no  marked  or  constant 
effect  upon  metabolism,  for  most  of  the  results  reported  in  the 
literature  are  very  contradictory,  some  observing  nitrogen  loss 
and  some  nitrogen  retention.4 

The  active  substance  has  been  isolated  in  pure  crystalline  form, 
and  although  various  names  have  been  given  to  it,  adrenalin  is 
the  one  in  most  general  use.  As  yet  unanimity  has  not  been 
reached  concerning  the  structural  composition  of  adrenalin,5  but 
it  is  unquestionably  related  to  pyrocatechin, 

-P       .  : 

and  the  formula  accepted  by  the  majority  of  chemists 6  is 
HO  /  >  -  CHOH  -  CH2  —  NH  -  CH3. 


This  view  of  its  structure  suggests  that  it  is  derived  from  the 
aromatic  groups  of  the  proteid  molecule.7  Dakin,8  starting  with 
pyrocatechin,  has  synthesized  a  substance  with  the  same  formula 
as  that  given,  which  has  physiological  effects  similar  to  those  of 
the  natural  adrenalin,  although  the  synthetic  substance  differs 
from  the  natural  in  being  optically  inactive. 

Important  as  this  substance  is,  its  production  is  probably  not 
the  sole  function  of  the  gland,  for  the  administration  of  adren- 

1  Moore  and  Purinton  (Amer.  Jour.  Physiol.,  1900  (4),  51)  state  that  the 
embryo  human  adrenal  has  no  effect  on  blood  pressure,  and  does  not  give  the 
characteristic  "  chromogen  "  reaction  with  ferric  chloride. 

2  Jour,  of  Physiol.,  1905  (33),  374. 

3  Ibid.,  1905  (32),  401. 

*Vollbracht,   Wien.  klin.   Woch.,  1899  (12),  737;  Pickardt,   Berl.   klin. 
Woch.,  1898  (35),  727;  Kaufmann,  Cent.  f.  Stoffwechsel,  1901  (2),  173. 

5  See  Abel  and  Taveau,  Jour.  Biol.  Chem.,  1905  (1),  1. 

6  See  Friedmann,  Hofmeister's  Beitr.,  1906  (8),  95. 

7  See  Halle,  Hofmeister's  Beitr.,  1906  (8),  276;  also  Friedmann, /oc.  cit. 

8  Jour,  of  Physiol.,  1905  (32),  p.  xxxiv;  Proc.  Koyal  Soc.,  1905  (76),  491. 


500   CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS  GLANDS 

alin  or  adrenal  extracts,  as  before  mentioned,  will  not  counter- 
act the  loss  of  the  adrenals.  Thus,  in  97  cases  of  Addison's 
disease  collected  by  Adams,1  treatment  with  adrenal  extract 
caused  some  improvement  in  31,  43  were  not  benefited,  7  were 
made  worse,  while  but  16  were  permanently  improved.  In  three 
cases  in  which  grafting  of  adrenal  tissue  was  performed,  the 
patients  seemed  to  have  been  made  worse.  It  is  possible  that 
the  cortical  and  medullary  portions  have  different  functions, 
since  the  latter,  which  contains  most  of  the  adrenalin,2  origi- 
nates in  the  sympathetic  nervous  system,  while  the  cortex  is 
formed  from  the  same  embryonal  tissue  elements  as  the  kidneys 
and  the  generative  glands.  In  rabbits  the  cortex  hypertrophies 
during  pregnancy ;  in  frogs  seasonal  variations  in  structure 
occur,  corresponding  to  the  period  of  mating;  and  cases  of  sex- 
ual precocity  have  been  found  associated  with  adrenal  hyper- 
trophy, while  cases  of  defective  sexual  development  have  been 
found  associated  with  adrenal  atrophy.  Therefore,  it  seems 
probable  that  the  cortical  portion  has  to  do  with  the  generative 
organs.  Karakaseheff3  believes,  however,  that  Addison's  dis- 
ease depends  upon  lesions  of  the  adrenal  cortex,  since  the 
medullary  part  may  be  entirely  destroyed  without  the  appear- 
ance of  the  disease.  The  view  that  a  diseased  condition  of  the 
semilunar  ganglion,  or  of  the  entire  sympathetic  nervous  sys- 
tem, is  the  cause  of  Addison's  disease  has  been  long  held  by 
many,  and  undoubtedly  bears  some  relation  to  the  observation 
of  Langley,4  that  the  effects  produced  by  adrenalin  upon  any 
tissue  are  such  as  follow  excitation  of  the  sympathetic  nerve 
which  supplies  the  same  tissue. 

The  amount  of  adrenalin  secretion  seems  to  be  little  modified 
by  disease  or  drugs  (atropin),  according  to  Ehrmann,5  although 
in  acute  experimental  infections  in  animals  the  amount  present 
in  the  gland  seems  to  be  decreased.  Adrenalin  is  not  readily 
destroyed  by  postmortem  autolysis  of  the  glands.6  In  chronic 
insanity  Mott  and  Halliburton7  found  the  adrenals  atrophied 
and  deficient  in  adrenalin  ;  this  condition  seems  to  be  due  to  the 
chronic  disease  and  not  specifically  related  to  the  insanity,  and 
the  authors  suggest  that  defective  vascular  tone  in  chronic  dis- 
eases may  be  partly  dependent  upon  adrenal  atrophy. 

Practitioner,  1903  (71),  472. 

2  See  Abelous,  Compt.  Rend.  Soc.  Biol.,  1905  (59),  520. 

'Ziegler's  Beitr.,  1904  (36),  401. 

4  Jour,  of  Physiol.,  1901  (27),  237. 

5  Arch.  exp.  Path.,  1906  (55),  39. 

6  See  Gazette  degli  Osped.,  1896,  No.  12. 

7  Jour,  of  Physiol.,  1906  (34),  p.  iii. 


ARTERIAL  DEGENERATION  FROM  ADRENALIN      501 

Arterial  Degeneration  from  Adrenalin. — An  interest- 
ing result  of  repeated  injections  of  adrenalin  into  animals  is  the 
appearance  of  a  marked  atheromatous  degeneration  of  the  aorta, 
with  calcification.  This  was  first  observed  by  Josue",  and  since 
confirmed  by  Erb,  Fischer,  Gouget,  Loeb  and  Githens,  and 
many  others.1  These  lesions  are  quite  different  from  those  of 
human  arteriosclerosis,  the  chief  change  being  degeneration  of 
the  muscle-cells  of  the  media,  without  any  considerable  inflam- 
matory reaction.2  They  do  not  seem  to  be  due  to  the  heightened 
blood  pressure,  since  simultaneous  administration  of  substances 
that  keep  the  blood  pressure  down  does  not  prevent  the  atheroma 
from  developing  (Braun),  while  other  substances  that  raise  blood 
pressure,  such  as  nicotine  (Josue")  or  pyrocatechin  (Loeb  and 
Githens),  do  not  cause  atheroma.  Presumably,  therefore,  adren- 
alin causes  the  arterial  changes  by  a  direct  toxic  action.3 
Myocardial  degeneration  is  also  observed  in  experimental  ani- 
mals, and  later  may  lead  to  an  interstitial  myocarditis  (Pearce4). 
These  experiments  suggest  the  possibility  that  oversecretion  of 
adrenalin  may  be  a  cause  of  arteriosclerosis,  but  there  is  no 
evidence  that  this  actually  occurs  in  man. 

Adrenalin  Glycosuria. — Another  interesting  effect  of  in- 
jection of  suprarenal  extracts  or  of  pure  adrenalin  is  the  marked 
glycosuria  that  follows.  This  property,  first  described  by  Blum 
and  directly  after  by  Croftan,  has  been  particularly  studied  in 
Herter' s  laboratory,  where  a  number  of  interesting  facts  have 
been  developed.5  Subcutaneous  injections  cause  less  glycosuria 
than  intravenous  or  intraperitoneal  injections,  while  most  minute 
quantities  of  adrenalin  cause  glycosuria  if  applied  directly  to 
the  surface  of  the  pancreas.6  The  glycosuria  seems  to  depend 
upon  an  increased  conversion  of  glycogen  into  sugar  in  the 


1  Literature  given  by  Loeb  and  Githens,  Amer.  Jour.  Med.  Sci.,  1905  (130), 
658;  by  Ellis,  Amer.  Med.,  1906  (11),  292 ;  and  by  Pearce  and  Stanton,  Jour. 
Exp.  Med.,  1906  (8),  74. 

*  See  Klotz,  Jour.  Exper.  Med.,  Aug.,  1906. 

3  According  to  v.  Koranyi  the  production  of  sclerosis  may  be  prevented  by 
iodin  administration  (Deut.  med.  Woch.,  1906  (32),  679)  ;  see  also  Cummins 
and  Stout,  Univ.  of  Penn.  Med.  Bull.,  July,  1906.  Pearce  and  Baldauf  (Amer. 
Jour.  Med.  Sci.,  1906  (132),  737)  suggest  that  local  anemia  due  to  constriction 
of  the  vasa  vasorum  is  the  cause  of  the  arterial  degeneration. 

*  Jour.  Exp.  Med.,  1906  (8),  400. 

5  Literature  by  Herter  and  Kichards,  Med.  News,  1902  (80),  201 ;  Herter, 
Amer.  Med.,  1902   (3),  771  ;    Herter  and   Wakeman,  Virchow's  Arch.,  1902 

169),  479;   ibid.,  Amer.  Jour.  Med.  Sci.,   1903  (125),  46;   Underbill   and 
ossen,  Amer.  Jour,  of  Physiol.,  1906  (17),  42. 

6  The  relation  of  the  pancreas  to  adrenalin  glycosuria  is  brought  into  ques- 
tion by  the  results  obtained  by  Underbill  (Jour,  of  Biol.,  1906  (1),  113)  and 
Velich,  Virchow's  Arch.,  1906  (184),  345. 


502  CHEMICAL  PATHOLOGY  OF  THE  DUCTLESS  GLANDS 

liver,1  perhaps  indirectly  through  some  alteration  in  the  action 
of  the  pancreas.  Experimental  manipulation  of  the  adrenals 
causes  glycosuria,  while  their  removal  is  followed  by  a  decrease 
in  the  amount  of  sugar ;  hence  it  is  possible  that  both  in  health 
and  in  disease  the  adrenals  may  have  an  important  influence  on 
carbohydrate  metabolism.  Iwanoff 2  has  found  that  adrenalin 
increases  the  rate  of  discharge  of  sugar  from  the  glycogen-rich 
liver  through  which  salt  solution  is  being  transfused,  which 
observation  suggests  that  possibly  adrenalin  acts  directly  upon  the 
glycogen-splitting  enzyme  of  the  liver-cells.  Underhill  and 
Clossen  3  suggest  that  adrenalin  acts  upon  the  liver  through  the 
sympathetic  nervous  system ;  they  believe  that  adrenalin  gly- 
cosuria bears  no  relation  to  human  diabetes. 

'See  Wolownik-Charkow,  Virchow's  Arch.,  1905  (180),  225. 
2  Cent.  f.  PhysioL,  1905  (19),  891. 
8  Loc.  tit. 


CHAPTER    XXI 

URIC-ACID  METABOLISM  AND  GOUT 

THESE  subjects  have  been  the  object  of  such  a  prodigious 
amount  of  research  that  it  is  far  beyond  the  scope  of  this  work 
to  review  the  history  and  the  details  of  the  investigations. 
Such  a  review  is  also  particularly  unnecessary,  since  it  can  be 
found  in  the  works  on  physiological  chemistry  and  various 
treatises  on  metabolism,  and  also  since  it  has  been  recently 
thoroughly  covered  in  English  by  Barker  and  by  McCrudden.1 
The  more  recent  advances  have  also  been  discussed  by  Chit- 
tend  en  in  his  Shattuck  Lecture,2  and  by  Mendel  in  his  Harvey 
Lecture.3 

Consequently  the  attempt  will  be  made  in  this  chapter 
merely  to  give,  as  briefly  as  possible,  the  views  now  most  gener- 
ally accepted  concerning  the  nature  and  metabolism  of  uric  acid, 
and  its  relation  to  pathological  processes.  For  the  historical 
discussion,  indicating  by  what  devious  steps  we  have  reached 
our  present  understanding  concerning  this  long-disputed  subject, 
the  reader  is  referred  to  the  articles  mentioned,  upon  which  I 
have  freely  drawn.  In  these  articles  will  be  found  a  complete 
bibliography  to  the  beginning  of  1906. 

THE  CHEMISTRY  OF  URIC  ACID 

It  is  the  very  great  service  of  Emil  Fischer  to  have  shown 
us  the  structure  of  the  uric-acid  molecule,  the  empirical  formula 
of  which,  C5H4N4O3,  had  long  been  known.  He  demonstrated 
that  it  is  a  member  of  a  group  of  substances,  which  are  all 
characterized  by  being  built  up  about  a  certain  nucleus,  C5N4. 
As  the  simplest  member  of  the  group  is  a  synthetically  formed 

1  L.  F.  Barker,  "  Truth  and  Poetry  Concerning  Uric  Acid,"  Chicago,  1905 ; 
this  will  also  be  found  as  a  series  of  editorials  under  the  same  title  in  the 
Journal  of  the  Amer.  Med.  Assoc.,  1905  (44), from  Jan.  14  to  May  13.   F.  H. 
McCrudden,  "Uric  Acid,"  New   York,  1906.     Other  complete  reviews  are 
given  by  Wiener,  Ergebnisse  der  Physiol.,  1902  (1),  555;  ibid.,  1903  (2),  377; 
Burian  and  Schur,  Pfluger's  Arch.,  1900  (80),  241;  1901  (87),  239;  Walker 
Hall,  "The  Purin  Bodies  of  Food-stuffs,"  1903. 

2  Boston  Med.  and  Surg.  Jour.,  1905  (153),  179. 

3  Journal  Amer.  Med.  Assoc.,  1906  (46),  843. 

503 


504  URIC-ACID  METABOLISM  AND  GOUT 

body,  purin,  the  nucleus  is  called  the  "purin  nucleus"  The 
structural  relations  of  the  better-known  "  purin  bodies  "  to  this 
purin  nucleus  and  to  each  other  is  clearly  shown  by  their  struc- 
tural formulae,  as  given  below  : 

The  atoms  in  the  "  purin  nucleus  "  are  arranged  as  follows  : 


« 
—  0(6)  — 


N 


(3)  —  Cu)  —  N(9) 

To  each  atom  has  been  given  a  number,  as  shown,  for  the  pur- 
pose of  facilitating  reference  to  the  location  of  various  atoms 
and  groups  that  are  attached  to  this  nucleus.  The  structure  of 
purin  itself  is  as  shown  below  :  1 

N  =  CH 
HO      0  —  NH 


-C-N 

Purin 

The  derivatives  of  purin  are  described  by  stating  to  which 
atom  of  the  purin  nucleus  the  combining  groups  are  attached. 
Thus,  adenin  is  referred  to  as  6-amino-purin,  and  therefore  has 
the  following  formula : 

N=C-NH2 
HO       0  — NH 


i 


-iUf 

Adenin  (6-amino-purin) 

Other  important  members  of  this  group  of  "purin  bodies," 
(also  called  xanthin  bodies,  alloxuric  bodies,  and  nuelein  bodies) 
are  built  up  about  the  purin  nucleus  as  shown  below  : 

N—  C  =  O  HN—  C  =  O 

H2N.C      0  — NH  O  =  C      0  — NH 


Guanin  Xanthin 

(2-amino-6-oxypurin)  (2, 6-dioxypurin) 

1  In  these  formulae  the  symbols  of  the  atoms  forming  the  purin  nucleus 
are  in  heavy  type. 


THE  CHEMISTRY  OF  URIC  ACID  505 


HN-C=0  HN-C=0 

HCJ-C-NH  O=0      0— NH 

I  I  >H  >c=a 

gL_6_jf  HN-C-NH 

Hypoxanthin  Uric  acid 

(6-oxypurin)  (2-6-8-trioxypurin) 

H3C-N  — 0  =  0 


>H 


HSC  — N-0- 


Caffein  Theobromine 

(1-3-7  trimethyl-2-6  dioxypurin)  (3-7-dimethyl,  2-6  dioxypurin) 

Properties  of  Uric  Acid. — Uric  acid,  when  pure,  is 
white,  and  crystallizes  in  rhombic  tablets.  Its  solubility 
is  very  slight;  at  room  temperature  (18°)  it  dissolves  but 
about  one  part  to  40,000  of  water,  so  that  a  saturated  solution 
contains  but  0.0253  gram  to  the  liter.  It  is  much  more  solu- 
ble in  blood-serum,  dissolving  in  1000  parts,1  probably  held 
in  some  complex  combination.  His  and  Paul  have  shown 
that  in  a  saturated  solution  only  9.5  per  cent,  of  the  molecules 
are  dissociated,  the  dissociation  occurring  in  two  steps ;  the  first 
and  chief  dissociation  is  into  H  and  C5H3N4O3,  which  then 
undergoes  further  dissociation  into  H  and  C5H2N4O3,  the  latter 
dissociation  being  very  slight.  If  any  other  acid  is  present 
in  the  solution,  its  dissociation  and  liberation  of  free  hydro- 
gen ions  interferes  with  the  dissociation  of  the  uric  acid,  and  as 
the  undissociated  uric  acid  is  extremely  insoluble,  the  amount 
dissolved  in  an  acid  solution  is  much  less  than  in  a  neutral 
solution. 

With  alkalies  uric  acid  yields  two  series  of  salts,  correspond- 
ing to  these  two  steps  in  dissociation  :  one,  in  which  one  atom 
of  the  base  enters,  is  called  the  biurate  or  monobasic  urate ;  the 
other  is  the  so-called  "  neutral "  or  bibasic  urate.2  Of  the  two, 
the  latter  is  much  the  more  soluble.  The  monosodium  urate 
forms  colloidal  solutions  in  water,  from  which  the  crystalline 
salt  gradually  falls  out. 

In  the  urine  the  uric  acid  and  the  urates  are  kept  in  solution 
by  the  phosphates,  the  disodium  phosphate  preventing  the 
decomposition  of  the  urates  into  uric  acid  by  the  acid  salts  of 
the  urine.  Possibly  other  constituents  of  the  urine,  especially 

Baylor,  Jour.  Biol.  Chem.,  1906  (1),  177. 

2  As  a  matter  of  fact,  both  salts  give  a  slightly  alkaline  reaction  when  dis- 
solved in  water  (Taylor). 


506  URIC-ACID  METABOLISM  AND  GOUT 

the  pigments,  also  aid  in  its  solution.  How  the  uric  acid 
is  kept  in  solution  in  the  blood  is  not  exactly  understood,  but 
it  seems  probable  that  it  is  in  combination  with  some  organic 
substance,  possibly  with  some  derivative  of  nucleic  acid. 


FORMATION    OF   URIC   ACID 

The  origin  of  uric  acid  is  chiefly,  although  not  exclusively, 
from  the  nucleoproteids,  and  it  is  customary  to  refer  to  uric 
acid  formed  from  the  nucleoproteids  of  the  foods  as  "  exogen- 
ous "  uric  acid,  in  contrast  to  the  "  endogenous  "  uric  acid  that 
is  formed  from  the  nucleoproteids  of  the  body  cells  during 
their  catabolism. 

This  may  be  readily  explained  by  a  brief  consideration  of 
the  composition  of  the  nucleoproteids.  The  nucleoproteids  may 
be  looked  upon  as  salts  formed  through  combination  of  proteids 
with  nucleic  acid.  Nucleic  acid  in  turn  is  a  compound  of 
phosphoric  acid  with  purin  bases,  pyrimidin  bases,  and  usually 
also  with  carbohydrate  radicals.  For  example,  the  following 
structural  formulae  have  been  proposed  as  indicating  the  com- 
position of  certain  nucleic  acids,  showing  (provisionally)  how 
pentose  radicals  (C,H9O5)  purin  radicals  (C5H4N5  and  C5H4N5O) 
and  pyrimidin  radicals  (C4H3N2O2)  may  be  grouped  about  phos- 
phoric-acid radicals  to  form  various  nucleic  acids : 

OH  OH  OH  OH  OFT 

\  /  \  /  / 

C5H905  -  P  -  C5H  A  C5H4N5  -  O  -  P  -  O  -  C3H5\ 

I  I  C5H905 

O  O 


HO.    \  /OH 

XP-C4H3N  A  C5H4N5  -  O  -  P  -  O  -  C3H5/ 


X'    |  XC5H905 

O  00 

!    /OH  \/  /OH 

HO—  P<  C5H4N5  —  O  -  P  —  O  —  C3H5 


I 
C5H,N6-0      Px-OH 

OH  OH  OH 

Triticonucleic  acid  (from  wheat  germ)  Guanylic  acid  (from  pancreas) 

Nucleic  acids  of  different  origins  differ  from  one  another  in 
the  number  and  variety  of  purin  bases  they  contain,  and  also 
in  their  carbohydrate  radicals,  hence  an  almost  infinite  variety 
of  nucleic  acids  and  nucleoproteids  may  exist. 

Uric  acid  itself  does  not  exist  in  the  nucleoproteid  molecule, 


FORMATION  OF  URIC  ACID  507 

but  it  is  readily  formed  from  any  of  the  purin  bases,  and  the 
steps  by  which  it  is  formed  are  believed  to  be  as  follows : 

Nucleoproteids  when  acted  upon  by  trypsin  have  the  proteid 
group  digested  away,  leaving  the  nucleic-acid  radical  unaffected. 
Probably  in  intracellular  metabolism  the  proteolytic  enzymes 
of  the  cell  have  a  similar  action  upon  the  nucleoproteids,  set- 
ting free  the  nucleic  acids,  which  are  then  attacked  by  a  specific 
enzyme  (or  enzymes)  called  by  Iwanoff  "  nudease."  This 
enzyme  liberates  from  the  nucleic  acid  the  purin  bases,  of  which 
adenin  and  guanin  are  the  most  abundant.1  These  two  sub- 
stances are  in  turn  acted  upon  by  other  specific  intracellular 
enzymes,  which,  through  hydrolysis  and  liberation  of  ammonia 
(deamidization),  convert  them  into  xanthin  and  hypoxanthin,  as 
shown  by  the  following  equation  : 

C5H5N60  +  H20 >  C5H4N402  +  NH, 

(guanin)  (guanase)    (xanthin) 

C5H5N6    +    H20  ->     C5H4N40    +    NH3 

(adenin)  (adenase)  (hypoxanthin) 

The  final  step,  the  conversion  of  the  xanthin  and  hypoxanthin 
into  uric  acid,  is  accomplished  through  oxidation  by  the  action 
of  an  oxidizing  enzyme.  First,  the  hypoxanthin  is  converted 
into  xanthin  : 

C6H4N40  +  O  -     —>  C5H4N402 

(hypoxanthin)      (oxidase)     (xanthin) 

and  the  xanthin  is  then  oxidized  into  uric  acid,  thus : 

C5H4N402  +  O  -     -  >  C5H4N403 

(xanthin)  (oxidase)   (uric  acid) 

Not  only  are  these  reactions  accomplished  in  the  body  during 
metabolism,  but  it  has  been  found  possible  to  obtain  enzyme- 
containing  extracts  from  the  tissues,  which  will  bring  about 
these  various  reactions  when  allowed  to  act  upon  pure  adenin, 
guanin,  etc.,  outside  the  body.  Each  reaction  seems  to  depend 
upon  a  specific  enzyme. 

Another  possible  source  of  uric  acid  is  through  synthesis.  In 
birds,  which  eliminate  most  of  their  nitrogen  in  the  form  of 
uric  acid,  synthesis  of  uric  acid  undoubtedly  occurs.  It  would 
seem  possible,  therefore,  for  synthesis  of  uric  acid  to  occur  in 
mammals,  but  as  yet  satisfactory  experimental  evidence  is  lack- 
ing that  such  synthesis  does  occur.  The  greater  part,  and  per- 
haps all,  of  the  uric  acid  is  formed  in  mammals  through  oxida- 
tion of  performed  purin  groups. 

1  See  review  by  Jones  and  Austrian,  Zeit.  pbysiol.  Chem.,  1906  (48),  110; 
also  full  summary  by  Bloch,  Biochemisches  Centralblatt,  1906  (5),  521. 


508  URIC-ACID  METABOLISM  AND  GOUT 

It  should  also  be  mentioned  that  not  all  of  the  purin  bases 
of  the  body  is  bound  in  the  form  of  nucleic  acid.  A  consider- 
able amount  is  present  in  a  free  condition,  or  at  least  not  bound 
in  nucleic  acid,  especially  in  muscle  tissue,  where  much  more  of 
the  purin  bases  is  free  than  combined.  Uric  acid  can  be 
formed  equally  as  well  from  the  free  purin  bases  as  from  purin 
bases  liberated  from  nucleic  acid  —  indeed,  evidence  has  recently 
been  brought  forward  indicating  that  a  large  proportion  of  the 
uric  acid  arising  during  metabolism  (endogenous)  comes  from 
the  free  hypoxanthin  of  the  muscles. 

As  to  the  place  where  uric  acid  is  formed,  it  seems  probable 
that  the  purin  bases  and  the  necessary  oxidative  enzymes  are 
present  in  many  if  not  in  all  varieties  of  cells  ;  certainly  all 
the  chief  visceral  tissues  and  the  muscles  are  capable  of  form- 
ing uric  acid. 

DESTRUCTION   OF  URIC   ACID 

By  no  means  all  of  the  purin  bases  that  is  formed  in  the 
tissues,  or  that  is  taken  into  the  alimentary  canal  in  the  food, 
appears  in  the  urine  as  uric  acid  ;  by  far  the  greater  part  is  des- 
troyed through  oxidation,  forming  urea  from  the  nitrogen-con- 


taming  groups,  and  oxalic  acid,  from  the  remaining  C 

C 

in  case  oxidation  is  not  complete.     The  relation  of  uric  acid  to 
urea  can  readily  be  seen  by  comparing  their  structural  formulae  : 

H2N  HN  —  C  =  O 

O=C  O=C      C—  NH 

I  I     II      >c=o 

H2N  HN—  C  —  NH 

(urea)  (uric  acid) 

Of  the  purin  bases  taken  in  the  food,  it  is  estimated  that 
in  carnivora,  such  as  dogs,  but  one-twentieth  to  one-thirtieth 
appears  in  the  urine  as  uric  acid  ;  in  herbivora  (rabbits),  one- 
sixth  ;  and  in  omnivora  (man),  one-half.  Apparently  the  purin 
bases  taken  in  the  food  are  first  converted  into  uric  acid  before 
being  destroyed,  for  it  has  been  found  that  if  uric  acid  is  injected 
into  an  animal,  the  same  amount  appears  in  the  urine  as  when  a 
corresponding  quantity  of  purin  bases  is  given  to  the  same  ani- 
mal by  mouth  or  subcutaneously. 


DESTRUCTION  OF  URIC  ACID  509 

The  steps  by  which  uric  acid  is  destroyed  are  not  known, 
except  that  in  any  case  the  nitrogen  is  eliminated  as  urea.  Experi- 
mental decomposition  of  uric  acid  in  the  laboratory  shows  that 
it  can  be  split  up  in  at  least  three  different  ways.  By  certain 
methods  it  yields  glycocoll,  ammonia,  and  carbon  dioxide ;  by 
another  method  the  products  are  first,  alloxan  (C4H2N2O4), 
which  later  yields  parabanie  acid  (C3H2N2O3),  and  this  in  turn 
yields  oxalic  acid  and  urea.  By  still  a  third  method  uric  acid 
is  decomposed  into  allantoin  (C4H6N4O3)  and  carbon  dioxide, 
and  the  allantoin  yields,  on  further  oxidation,  urea  and  oxalic 
acid,  thus : 


NH  — CH  — NH  NH2  COOH 

0=0                   C  =  0  +  0   +   2H20  =  20C  + 

NH— CO      NH2  NH2  COOH 

(allantoin)  (urea)  (oxalic  acid) 


It  seems  quite  probable  that  allantoin  is  one  of  the  first  steps 
in  the  metabolic  oxidation  of  uric  acid  in  the  body,  for  if 
excessive  quantities  of  uric  acid  or  of  purin-rich  foods  are  fed 
to  dogs,  a  large  amount  of  allantoin  appears  in  the  urine.  As 
smaller  quantities  of  purins  are  completely  oxidized,  it  seems 
probable  that  the  excessive  amounts  cannot  be  completely 
oxidized  and  are  eliminated  while  in  the  allantoin  stage.  Allan- 
toin seldom  appears  in  human  urine,  except  in  young  infants 
and  pregnant  women,  in  both  of  which  cases  the  cause  may 
be  either  deficient  oxidation  or  excessive  destruction  of  tissue 
nucleins.  However,  there  is  also  evidence  that  glycocoll  is 
formed  in  the  tissues  from  uric  acid,  and  hence  it  is  possible 
that  uric  acid  may  be  broken  down  along  more  than  one  of  the 
lines  of  decomposition  indicated  above.  In  any  case,  however, 
the  destruction  of  uric  acid  depends  upon  oxidation,  and  is, 
therefore,  but  a  continuation  of  the  process  by  which  the  purin 
bases  are  converted  into  uric  acid. 

The  destruction  seems  to  take  place  chiefly  in  the  liver,  kidney, 
and  muscles,  extracts  of  these  organs  being  capable  of  destroying 
uric  acid  in  vitro  ;  but  little  or  no  uric  acid  is  destroyed  in  the 
lungs,  spleen,  and  blood.  In  different  species  of  animals  the 
amount  of  destruction  in  the  liver  and  kidney  varies,  in  carnivora 
the  liver  being  most  active,  as  shown  by  Burian  and  Schur, 
who  found  that  in  nephrectomized  dogs  no  uric  acid  appears  in 
the  blood,  but  on  excluding  the  liver  from  the  circulation,  uric 
acid  at  once  appears.  In  herbivora  the  kidneys  seem  to  be 
more  actively  uricolytic.  This  difference  perhaps  depends  upon 


510  URIC -ACID  METABOLISM  AND  GOUT 

the  large  amount  of  purin  bodies  brought  to  the  liver  from  the 
animal  food  of  the  carnivora.  In  man  the  kidney  is  also  most 
active,  although  if  the  bulk  of  the  organs  be  taken  into  account, 
in  man  the  muscles  destroy  most  uric  acid,  next  the  kidneys, 
and  then  the  liver  (Croftan).  The  destruction  seems  to  be 
accomplished  by  specific  uricolytic  enzymes,  which  are  of  the 
nature  of  oxidizing  enzymes,  although  it  may  be  that  some 
other  enzymes  must  first  split  the  uric-acid  molecule  to  prepare 
it  for  oxidation. 

THE   OCCURRENCE  OF  URIC  ACID    IN  THE  BLOOD,  TISSUES, 
AND  URINE 

As  can  be  seen  from  the  foregoing  discussion,  the  amount  of 
uric  acid  that  appears  in  the  urine  depends  upon  a  number  of 
factors,  which  may  be  enumerated  as  follows  :  (1)  The  amount 
of  purin  bodies  taken  in  the  food,  upon  which,  chiefly,  depends 
the  amount  of  exogenous  uric  acid.  (2)  The  amount  of  destruc- 
tion of  tissue  nucleoproteids.  (3)  The  amount  of  purin  bases 
formed  in  the  muscle  tissue.  (4)  The  amount  of  conversion 
of  purin  bases  into  uric  acid.  (5)  The  amount  of  destruction 
of  uric  acid  occurring  in  the  body.  (6)  Possibly  upon  the 
capacity  of  the  tissues  to  synthesize  uric  acid  ;  and  in  case  such 
power  to  synthesize  uric  acid  exists,  upon  the  presence  of  the 
precursors  of  uric  acid  in  the  body.  (7)  The  retention  of  uric 
acid  in  the  blood  and  tissues.  (8)  The  power  of  the  kidneys 
to  excrete  uric  acid. 

If  we  also  take  into  account  the  fact  that  the  solubility  of 
uric  acid  in  the  urine  depends  chiefly  upon  the  amount  of 
neutral  phosphates  present  in  the  urine,  and  also  upon  the 
temperature,  reaction,  and  concentration  of  the  urine,  it  becomes 
apparent  how  totally  devoid  of  significance  is  the  presence  of 
crystals  of  uric  acid  and  urates  in  the  urine,  and  how  fallacious  is 
any  theorization  based  upon  the  excretion  of  considerable  quanti- 
ties of  uric  acid  when  all  the  above-mentioned  factors,  especially 
the  diet,  are  not  controlled  and  taken  into  consideration.  Yet 
on  just  such  an  inadequate  basis  has  been  constructed  an 
enormous  amount  of  theorization  as  to  "  uric-acid  diathesis," 
"  uric-acid  intoxication/'  "  lithemia,"  etc.,  until  it  has  come  to 
be  popularly  believed  that  a  large  share  of  the  minor  ailments 
of  humanity,  and  in  particular  all  non-infectious  diseases  of  the 
joints  and  muscles,  are  dependent  upon  the  presence  of  excessive 
quantities  of  uric  acid  or  urates  in  the  blood.  But  it  may  be 
safely  stated  that  at  the  present  time  there  exists  no  good 
evidence  which  makes  it  probable  that  uric  acid  is  responsible 


GOUT  511 

for  any  pathological  conditions  whatever,  except  uric-acid  calculi, 
"  uric-acid  infarcts  "  in  the  kidneys,  and  certain  manifestations 
of  gout.  Uric  acid  is  possessed  of  but  a  very  slight  degree 
of  toxicity,  and  the  body  is  able  to  destroy  it  in  such  large 
measure  that  an  actual  intoxication  with  uric  acid  probably 
never  occurs. 

The  amount  present  in  the  urine  may  be  very  considerably 
increased  by  eating  food  rich  in  purins,  of  which  sweet-breads, 
liver,  and  kidney  are  the  best  examples  ;  and  also  coffee  with  its 
caffein  (trimethyl  purin  l).  Large  quantities  of  meat  will  also 
increase  the  uric  acid,  because  of  the  free  purius  contained  in 
muscle.  However,  the  amount  of  uric  acid  in  the  blood  is  not 
correspondingly  raised,  this  being  regulated  by  the  destructive 
and  binding  function  of  the  tissues,  arid  by  excretion  through  the 
kidneys.  Whenever  much  destruction  of  the  nucleoproteids  of 
the  tissues  is  occurring  in  the  body,  the  elimination  of  endogenous 
uric  acid  becomes  abnormally  raised,  the  best  examples  being 
the  resolution  of  pneumonic  exudates,  and  leukemia,  especially 
leukemia  under  #-ray  treatment  (q.  v.).  In  neither  of  these 
conditions,  however,  can  any  symptoms  or  tissue  changes  be 
referred  to  the  excessive  uric  acid.  It  is  quite  possible  that 
the  power  of  the  body  to  oxidize  uric  acid  may  be  decreased 
under  certain  conditions ;  thus,  alcohol  is  found  to  cause  a 
decided  increase  in  uric-acid  elimination,  particularly  after 
purin-rich  foods  have  been  taken  (Chittenden),  and  this  effect 
is  ascribed  to  lessened  uric-acid  destruction.  However,  we 
have  no  evidence  that,  except  possibly  in  gout,  this  decreased 
destruction  of  uric  acid  under  the  influence  of  alcohol  causes 
harm.  It  has  been  shown  that  severe  organic  lesions  involv- 
ing the  liver  (phosphorus  poisoning)  do  not  cause  a  marked 
decrease  in  the  power  of  oxidizing  uric  acid. 

GOUT 

After  adjusting  the  many  contradictory  statements  of  earlier 
investigators,  the  present  status  of  our  conception  of  uric-acid 
metabolism  in  gout  may  be  briefly  summarized  as  follows  :  The 
excretion  of  uric  acid  in  patients  with  chronic  gout,  when  kept 
upon  a  definite  diet,  does  not  differ  from  the  excretion  of  normal 
individuals  on  the  same  diet,  except  in  cachectic  arthritics,  with 
whom  the  elimination  of  uric  acid  is  small.  Normally  the 
elimination  of  uric  acid  varies  within  rather  wide  limits,  even  on 

1  Concerning  the  effect  of  diet  upon  purin  excretion  see  Taylor,  Amer. 
Jour.  Med.  Sci.,  1899  (118),  141. 


512  URIC-ACID  METABOLISM  AND  GOUT 

a  constant  diet,  and  the  variations  in  chronic  gout  fall  within 
the  same  limits.  There  is  always  an  increased  amount  of  uric 
acid  in  the  blood  in  gout,  but  no  constant  increase  can  be  noted 
preceding  the  attack  (Magnus-Levy).  In  the  intervals  between 
the  attacks  of  acute  gout  the  elimination  of  uric  acid  remains 
within  the  normal  limits  ;  however,  for  a  period  of  one  to  three 
days  before  each  acute  attack  the  amount  of  uric  acid  is 
usually  decreased  considerably.  With  the  onset  of  the  attack 
the  amount  of  uric  acid  excreted  becomes  increased,  and  for  a 
few  days  remains  above  the  average,  then  subsides  to  about  the 
normal.  Of  these  two  features,  the  increased  output  of  uric 
acid  during  the  attack  seems  to  be  more  constant  than  the 
reduced  output  preceding  it. 

As  yet,  however,  we  have  no  definite  information  either  as  to 
the  cause  of  this  behavior  of  the  uric  acid  during  the  paroxysms 
of  acute  gout,  or  as  to  its  part  in  causing  the  paroxysm.  How- 
ever, in  view  of  the  fact  that  monosodium  urate  is  found  in  the 
joints  during  the  attacks,  it  seems  most  probable  that  for  some 
as  yet  unknown  reason  there  occurs  a  precipitation  or  anchoring 
of  the  urates  in  the  tissues,  which  is  associated  with  the  attacks 
of  pain  and  swelling.  We  do  not  know,  however,  that  it  is  the 
deposition  of  urates  that  causes  the  attacks.  Indeed,  the  fact 
that  uric-acid  retention  precedes  the  attack,  rather  than  accom- 
panies it,  seems  to  suggest  that  it  is  the  absorption  of  the 
urate  rather  than  its  deposition  in  the  joints  that  is  responsible 
for  the  local  disturbances.  It  is  also  possible  that  during  the 
period  of  retention  the  uric  acid  is  held  in  the  blood  in  some 
form  that  cannot  be  eliminated  by  the  kidney,  and  that  its 
deposition  in  the  joints  in  an  absorbable  form  occurs  simultan- 
eously with  the  attack. 

It  should  be  mentioned  in  addition  that  it  is  not  the  uric-acid 
metabolism  alone  that  is  altered  in  gout.  Irregular  periods  of 
nitrogen  retention  and  nitrogen  loss  are  quite  constant  features. 
The  cause  of  this  variability,  and  the  form  in  which  the  nitrogen 
is  retained,  are  quite  unknown,  although  there  is  some  evidence 
that  the  retained  nitrogen  is  in  the  form  of  purin  bodies  (Vogt). 
Most  of  the  excessive  loss  occurs  during  the  acute  attacks,1 
and  the  retention  of  nitrogen  between  attacks  may  be  partly 
to  repair  the  loss ;  against  this,  however,  is  the  fact  that  there 
is  not  sufficient  gain  in  weight  to  account  for  all  of  the 
nitrogen  retention.  The  statements  in  regard  to  phosphoric 
acid  elimination,  which  depends  largely  on  decomposition  of 

1  Brugsch,  Zeit.  exp.  Path.  u.  Ther.,  1906  (2),  619. 


GOUT  513 

nucleins,  are  contradictory,  but  it  seems  probable  that  it  shows 
no  characteristic  alterations  in  gout. 

It  may  be  seen  from  the  foregoing  discussion  that  we  neither 
understand  fully  the  intricacies  of  metabolism  in  gout,  nor  know 
whether  uric  acid  is  responsible  for  either  the  acute  painful 
attacks  or  for  the  anatomical  alterations  in  the  kidneys,  heart, 
and  bloodvessels.  It  is  very  possible  that  some  entirely  different 
product  of  metabolism  than  uric  acid  is  responsible  for  most  of 
the  changes  and  symptoms  of  gout1 — indeed,  this  would  seem  to 
be  the  case  were  it  not  for  the  great  frequency  of  the  deposition 
of  monosodium  urate  in  the  joints  and  cartilages,  both  during  the 
acute  attacks  and  in  chronic  gout.  This  indicates  that  there  is 
surely  something  abnormal  in  the  conditions  of  uric-acid  solution 
and  circulation.  Why  the  urate  is  precipitated  in  these  definite 
places  is  another  of  the  many  unsolved  problems  of  gout.  That 
it  is  due  to  an  excess  of  uric  acid  in  the  blood  seems  to  have 
been  excluded,  and  there  is  no  good  evidence  that  the  precipita- 
tion depends  upon  a  decreased  alkalinity  of  the  blood — two 
ideas  once  in  vogue.  The  local  nature  of  the  deposition  indi- 
cates that  it  must  depend  upon  local  changes ;  but  the  hypoth- 
esis that  there  occur  first  degenerative  changes  in  the  tissues 
which  determine  the  precipitation  of  the  urate,  seems  to  have 
been  disproved  by  the  demonstration  that  the  deposition  df  the 
urates  precedes  the  necrosis.  The  histology  of  urate  deposits, 
both  experimental  and  gouty,  has  been  carefully  studied  by 
Freudweiler,2  His,3  Kratise,4  and  Rosenbach.5 

Their  results  all  indicate  that  uric  acid  and  urates  excite 
some  slight  inflammatory  reaction,  cause  a  slight  local  necrosis, 
and  seem  to  act  as  a  weak  tissue  poison  (His).  However, 
they  may  be  deposited  without  causing  necrosis  (Rosenbach). 
Possibly  part  of  the  material  observed  in  areas  of  urate  deposi- 
tion, and  generally  considered  as  necrotic  tissue,  merely  repre- 
sents the  framework  of  the  crystalline  deposit  (Krause).  When 
experimentally  injected,  the  urates  are  absorbed  slowly  by 
phagocytic  leucocytes  and  giant-cells.  Why  the  gouty  tophi 
can  be  deposited  in  the  chronic  process  and  cause  no  pain 
or  inflammation,  while  in  acute  gout  deposition  of  urates 
seems  to  cause  such  marked  symptoms,  is  also  an  unanswered 
question ;  unless  we  accept  the  explanation  that  the  slower 

1  In  swine  a  "  guanin  gout "  occurs ;  see  Schittenhelm  and  Bendix,  Zeit. 
physiol.  Chem.,  1906  (48),  140. 

2  Deut.  Arch.  klin.  Med.,  1899  ( 63),  266. 

3  Ibid.,  1900  (67),  81. 

4  Zeit.  klin.  Med.,  1903  (50),  136. 

5  Virchow's  Arch.,  1905  (179),  359. 

33 


514  URIC-ACID  METABOLISM  AND  GOUT 

rate  of  deposition  and  the  lack  of  dissolved  urates  account  for 
the  absence  of  symptoms  with  the  tophi.1 

That  urates  may  cause  necrosis  of  the  tissues  has  been 
definitely  established,  and  this  may  lead  to  connective-tissue 
formation  and  contraction.2  But  the  actual  increase  of  uric 
acid  in  the  blood  and  tissues  in  gout  is  so  slight  that  we  are  not 
warranted  in  saying  that  the  usual  tendency  to  sclerosis  in  all 
the  organs  in  gout  is  due  to  the  action  of  uric  acid,  rather 
than  to  some  other  unknown  agent  or  agents.  Excess  of  uric 
acid  in  the  blood  is  by  no  means  pathognomonic  of  gout,  for  it 
has  been  observed  also  in  nephritis,  in  diseases  with  corpuscle 
destruction,  and  after  taking  purin-rich  food.  Furthermore, 
it  is  quite  possible  that  the  precursors  of  uric  acid,  the  purin 
bases,  are  responsible  for  more  harm  than  the  uric  acid  itself. 
Thus,  administration  of  adenin  to  dogs  and  rabbits  will  produce 
degenerative  changes  in  the  kidneys,  associated  with  the  depo- 
sition of  substances  resembling  uric  acid  and  urates  in  the  renal 
tissue ;  and  Mandel 3  states  that  purin  bases  may  cause  fever, 
independent  of  infection.  In  this  connection  it  may  be  men- 
tioned that  many  have  looked  upon  renal  alterations,  leading  to 
failure  of  excretion  of  uric  acid,  as  the  primary  cause  of  gout ; 
but  the  evidence  in  favor  of  this  is  faulty,  because  frequently 
renal  changes  are  slight  or  entirely  absent  in  gout,  whereas 
marked  nephritis  of  all  forms  may  exist  without  the  coexist- 
ence of  gout. 

URIC-ACID  INFARCTS 

Uric-acid  infarcts,  as  the  deposits  of  urates  and  uric  acid  ob- 
served in  the  kidneys  of  at  least  half  of  all  children  dying 
within  the  first  two  weeks  of  life  are  called,  give  evidence  of 
the  slightness  of  the  toxic  effects  of  these  substances  upon  the 
tissues.  Usually  little  or  no  change  occurs  in  the  renal  tubules 
as  a  result  of  these  depositions,  except  such  as  can  be  attributed 
to  their  mechanical  effect.4  The  reason  for  the  formation  of  these 

1  Almagia  (Hofmeister's  Beitr.,  1905  (7),  466)  has  found  that  joint  carti- 
lage placed  in  urate  solutions  becomes  filled  with  crystals,  which  infiltration 
does  not  occur  with  cartilage  of  any  other  origin,  or  with  tendons. 

2  Because  the  gouty  tophi  do  not  suppurate,  even  when  ulcerated  through 
the  skin,  it  has   been   suggested  that  the  urates  have  antiseptic  properties. 
Bendix  (Zeit.  klin.  Med.,  1902  (44),  165),  however,  could  not   demonstrate 
such  antiseptic  properties  experimentally. 

3  Amer.  Jour.  Physiol.,  1904  (10),  452. 

4  I  have  recently  observed  a  case  of  fatal  hematuria  neonatorum,  associated 
with  most  extensive  hemorrhagic  infarction  of  both  kidneys.     In  the  bloody 
urine  B.  coli  was  found  in  large  numbers.     From  the  anatomical  findings  and 
history  it  seemed  quite  possible  that  the  injury  of  the  kidneys  by  uric-acid 
infarcts  might  have  determined  the  localization  of  the  bacteria  in  these  organs, 
with  resulting  hemorrhages. 


URIC-ACID  INFAECTS  515 

infarcts  is  not  at  all  understood.  Spiegelberg 1  found  it  possible 
to  cause  them  experimentally  in  young  dogs,  in  which  they  do 
not  occur  naturally,  by  injection  of  0.25  gram  of  uric  acid  per 
kilo.  He  was  unable  to  explain  why  this  deposition  should 
occur  in  young  animals  but  not  in  old,  for  he  could  not  find  evi- 
dence of  lessened  oxidative  power  on  the  part  of  young  animals, 
and  the  solvent  power  of  infants'  urine  was  found  equal  to  or 
greater  than  that  of  adults.  Other  authors,  however,  have 
found  a  lower  oxidative  power  in  young  animals,  and,  as  favor- 
ing the  idea  that  infants  have  less  power  to  oxidize  uric  acid 
than  adults,  is  the  fact  that  allantoin  has  been  found  in  their 
urine.  Possibly  the  uric-acid  infarcts  of  infants  are  the  result 
of  the  great  destruction  of  nucleoproteids  that  results  from  the 
change  of  the  nucleated  fetal  red  corpuscles  to  the  non-nucleated 
adult  form.  McCrudden  considers  the  high  concentration  of 
infants'  urine  an  important  factor.  Minkowski 2  observed  that 
administration  of  adenin  to  dogs  led  to  a  deposition  of  uric 
acid  or  some  similar  substance  in  the  kidneys.  Schittenhelm  3 
found  the  same  deposits  in  the  kidneys  of  rabbits  fed  adenin,  but 
not  when  they  were  fed  guanin.  According  to  Nicolaier,4  the  crys- 
tals thus  deposited  are  not  uric  acid  or  urates,  but  6-amino-2-8- 
dioxypuriu,  derived  from  the  adenin  (6-amino-purin)  by  direct 
but  incomplete  oxidation.  He  could  not  find  this  substance  in 
either  human  urine  or  in  a  uric-acid  calculus.  These  experi- 
mental infarctions  are  undoubtedly  related  to  the  human  form, 
and  indicate  that  the  latter  depend  upon  the  presence  of  an  ex- 
cessive amount  of  unoxidized  uric  acid  in  the  body. 

1  Arch.  exp.  Path.  u.  Pharrn.,  1898  (41),  428. 

2  Arch.  exp.  Path.  u.  Pharm.,  1898  (41),  375. 

3  Ibid..  1902  (47),  432. 

*Zeit.  klin.  Med.,  1902  (45),  359. 


CHAPTEK    XXII 

DIABETES 

As  with  gout,  diabetes  has  been  the  subject  of  such  an 
enormous  amount  of  discussion  and  experimentation  that  it  is 
impossible  in  this  place  to  attempt  to  review  the  entire  history 
and  literature  of  the  subject,  which  has  already  been  thoroughly 
done  by  a  number  of  physiological  chemists  and  clinicians  in 
the  places  cited  below.1  In  this  chapter  will  be  given  as 
briefly  as  possible  merely  an  epitome  of  the  views  now  held  by 
the  best  authorities  concerning  diabetes,  and  the  problems  of 
carbohydrate  metabolism  in  as  far  as  they  relate  to  diabetes. 

Diabetes  is  usually  distinguished  from  transient  forms  of 
glycosuria,  although  it  is  well  understood  that  no  sharp  line 
between  many  conditions  of  transient  glycosuria  and  chronic 
glycosuria,  or  diabetes,  can  always  be  drawn.  In  diabetes  the 
sugar  present  in  the  urine  is  predominantly  dextrose,  small 
quantities  of  levulose  and  other  sugars  frequently  accompany- 
ing it.  There  exist  cases,  however,  in  which  the  urine  contains 
for  a  long  period  of  time  other  sugars,  particularly  levulose 
and  pentose,  but  these  cases  are  not  associated  with  the  pro- 
found systemic  disturbances  of  diabetes,  presumably  because 
these  sugars  are  not  of  such  great  importance  for  the  nutrition 
of  the  body  as  is  dextrose. 

Glycosuria  may  be  produced  by  many  different  causes,  which 
may  be  grouped  under  the  following  heads  :  (1)  alimentary  ;, 
(2)  nervous;  (3)  drugs  and  other  chemicals;  (4)  pancreatic. 

I.    ALIMENTARY  GLYCOSURIA 

Under  ordinary  conditions  the  sugars  taken  with  the  food,, 
or  formed  from  the  carbohydrates  of  the  food,  are  in  large  part 
converted  into  glycogen,  and  temporarily  stored  in  this  form. 
The  arterial  blood  contains  quite  constantly  a  small  amount  of 

'Pfliiger,  Pfliiger's  Arch.,  1903  (96),  1 ;  v.  Noorden,  "Die  Zuckerkrank- 
heit  und  ihre  Behandlung"  ;  also  translation  of  his  Herter  lectures,  entitled, 
"Diabetes  Mellitus,"  New  York,  ]905,  (without  bibliography);  Macleod, 
pp.  312-386,  in  "Kecent  Advances  in  Physiology  and  Biochemistry,"  London, 
1906;  Abderhalden,  "  Lehrbuch  der  physiologischen  Chemie,"  Berlin,  1906, 
pp.  13-108.  Eeferences  will  generally  be  cited  only  when  not  contained  in  the 
above  reviews. 

516 


ALIMENTARY  GLYCOSURIA  517 

sugar,  which  varies  little  under  normal  conditions  from  0.1 
per  cent,  or  one  part  in  a  thousand.  By  converting  the  sugar 
brought  to  it  in  the  portal  blood  into  glycogen,  the  liver  main- 
tains the  proportion  of  sugar  in  the  blood  constant  at  this 
small  figure.  The  power  of  the  liver  to  store  up  glycogen  is 
not  unlimited,  however,  and  hence  if  too  large  quantities  of 
sugar  are  absorbed  into  the  portal  vein  in  a  short  space  of  time, 
not  all  of  it  is  converted  into  glycogen  in  its  passage  through 
the  liver,  and  consequently  the  systemic  blood  becomes  loaded 
with  more  than  the  normal  amount  of  sugar.  As  soon  as  this 
happens  the  urine  begins  to  contain  sugar,  for,  while  the  kidney 
does  not  excrete  more  than  the  most  minute  traces  of  sugar 
from  the  normal  blood,  yet  any  excessive  sugar  is  eliminated  at 
once.  The  explanation  of  this  will  be  discussed  later. 

Since  the  storage  of  sugar  as  glycogen  is  performed  chiefly 
by  the  liver,  this  fact  has  been  used  clinically  as  a  test  of  the 
functional  capacity  of  the  liver.  A  normal  individual  can  take 
from  150  to  200  grams  of  glucose  at  one  time  without  glyco- 
suria  resulting ;  therefore,  if  after  administration  of  somewhat 
smaller  quantities,  say  100  grams,  sugar  appears  in  the  urine, 
we  have  evidence  that  the  liver  is  functionally  incapacitated. 
Thus,  in  cirrhosis  of  the  liver  glycosuria  often  follows  the 
taking  of  100  grams  or  less  of  glucose.  This  "assimilation 
limit"  varies  under  normal  conditions  for  different  carbohy- 
drates.1 Unlimited  quantities  of  starch  may  be  taken,  because 
its  rate  of  conversion  into  sugar  is  slow  enough  to  prevent  an 
overwhelming  of  the  portal  blood  with  glucose.  Of  the  sugars, 
glucose  has  the  highest  assimilation  limit  (150—200  grams); 
but  that  of  levulose  is  about  as  high2  (140-160  grams),  and 
the  sugar  eliminated  in  the  urine  when  levulose  is  taken  is 
chiefly  glucose  mixed  with  some  levulose  (v.  Noorden).  Cane- 
sugar  has  about  the  same  assimilation  limit  as  glucose,  but  lac- 
tose (milk-sugar)  has  a  limit  of  120  grams  or  less.  With  the 
two  disaccharides  just  named,  any  excess  that  is  absorbed 
unchanged  from  the  intestine  into  the  blood  reappears  in  the 
urine,  for  they  cannot  be  utilized  by  the  liver  or  other  tissues ; 
maltose  alone  of  the  disaccharides  can  be  split  in  the  blood, 
where  a  specific  ferment,  maltase,  is  normally  present.  Pen- 
tosescan  be  assimilated  to  but  a  very  moderate  degree,  for  when 
even  so  little  as  30  to  50  grams  is  taken  by  mouth,  a  large 
amount  may  reappear  in  the  urine. 

1  See  Blumenthal,  Hofmeister's  Beitr.,  1905  (6),  329. 

2 1.9  gm.  per  kilo  in  man,  according  to  De  Kossi  (Kiforma  Med.,  1904  (20), 

729). 


518  DIABETES 

Pentosuria. — Pentoses  are  the  chief  carbohydrate  groups  of  the 
nucleoproteids,  but  they  are  also  present  in  many  vegetables  and  fruits. 
Some  persons  seem  to  lack  in  some  respects  the  power  of  utilizing  pen- 
toses,  and,  therefore,  exhibit  a  chronic  pentosuria,1  while  at  the  same 
time  they  can  utilize  other  sugars  without  difficulty.2  They  eliminate 
pentose  in  the  urine  even  when  there  is  none  in  the  food,  but  seem  able 
to  utilize  pentose  taken  in  the  food  nearly  as  well  as  normal  individuals. 
According  to  Neuberg,  the  pentose  found  in  the  urine  is  not  the  same 
as  that  of  the  nucleoproteids,  and  is  possibly  derived  from  the  hexoses.3 
This  condition  is  not  associated  with  constitutional  disturbances,  and 
must  be  considered  as  an  anomaly  in  metabolism  similar  to  cystinuria 
and  alkaptonuria,  especially  since  it  may  occur  as  a  family  disease. 
True  diabetes  may  also,  in  certain  cases,  be  looked  upon  as  an  hereditary 
metabolic  disorder,  in  view  of  the  frequently  observed  occurrence  of  the 
disease  as  a  family  peculiarity.  Lorand  *  has  observed  that  the  children 
of  diabetics  may  show  a  defective  power  of  sugar  assimilation. 

Levuiosuria,  in  which  levulose  is  eliminated  in  the  urine  on  a  diet 
containing  moderate  amounts  of  levulose,  is  a  rare  condition.  Neubauer  5 
has  collected  reports  of  five  cases  in  which  levulose  alone  was  present  in 
the  urine,  without  dextrose  being  present.  As  levulose  is  apparently 
converted  into  glycogen,  which  then  breaks  down  into  glucose,  the  fail- 
ure of  assimilation  of  levulose  in  these  patients  would  seem  to  be  due  to 
a  failure  of  the  conversion  of  levulose  into  glycogen.  Neubauer  observed 
in  his  case  that  a  definite  proportion  (15-17  per  cent.)  of  the  levulose 
given  by  mouth  was  excreted  in  the  urine,  and  suggests  as  an  alternative 
hypothesis  that  a  certain  proportion  of  the  levulose  of  the  food  is  directly 
oxidized  without  formation  of  glycogen,  and  that  failure  of  this  oxida- 
tion may  be  the  cause  of  levulosuria.  Mixed  levulosuria  and  glycosuria 
is  relatively  frequent,  and  in  some  cases,  at  least,  the  levulose  in  the 
urine  seems  to  have  been  derived  from  the  glucose  in  the  body  and  not 
from  the  levulose  of  the  food. 

Lactosuria,  or  excretion  of  milk-sugar  in  the  urine,  has  rarely  been 
observed  as  a  form  of  alimentary  glycosuria,  but  is  frequently  observed 
in  connection  with  formation  of  milk  in  the  mammary  gland  both  before 
and  after  parturition.6  After  resection  of  the  mammary  glands  lacto- 
suria  does  not  occur  (Moore  and  Parker7). 

Alimentary  glycosuria,  following  administration  of  small 
quantities  of  glucose,  does  not  necessarily  mean  that  the  func- 
tion of  the  liver  is  primarily  decreased ;  in  some  cases  the 

1  Literature  reviewed  by  Neuberg,  Ergebnisse  der  Physiol.,  1904  (3,  Abt.  1), 
373;   Wohlgemuth,  Biochem.  Centralbl.,  1903  (1),  533.     More  recent  articles 
by    Jolles,  Cent.  f.  inn.  Med.,  1905  (26),  1049 ;  Adler,  Pfliiger's  Arch.,  1905 
(110),  625;  Tintemann,  Zeit.  klin.  Med.,  1905  (58),  190;  Erben,  Prag.  med. 
Woch.,  1906    (31),  301;  Blum,  Zeit.  klin.  Med.,  1906  (59),  244  ;  Janeway, 
Amer.  Jour.  Med.  Sci.,  1906  (132),  423. 

2  Pentosuria  may  be  associated,  or  occur  alternately,  with  glycosuria  ;  see 
Kaplan,  New  York  Med.  Jour.,  1906  (84),  233. 

5  Many  unfermented  fruit-juices — e.  r/.,  apple-juice — contain  much  pentose, 
which  may  cause  alimentary  pentosuria  when  taken  in  large  amounts  (v. 
Jaksch,  Cent.  f.  inn.  Med.,  1906  (27),  145). 

4  Practitioner,  1903  (71),  522. 

5  Munch,  med.  Woch.,  1905  (52),  1525  (full  literature). 

6  Full  review  by  Porcher,  "  De  la  Lactosuria,"  Paris,  1906. 

7  Amer.  Jour.  Physiol.,  1900  (4),  239. 


NERVOUS  GLYCOSURIA  519 

defect  may  lie  in  the  nervous  system,  in  some  cases  in  the  pan- 
creas, the  relation  of  which  organs  to  glycosuria  will  be  con- 
sidered later ;  but  in  any  case  of  alimentary  glycosuria  the 
difficulty  lies,  either  primarily  or  secondarily,  with  the  liver, 
which,  for  one  reason  or  another,  cannot  convert  all  the  glucose 
into  glycogen.  If  the  liver  is  primarily  affected,  it  is  usually 
found  that  assimilation  of  levulose  is  more  affected  than 
assimilation  of  glucose,  and  hence  levulose  is  more  useful  in 
determining  "  hepatic  insufficiency  "  than  is  glucose. 

Why  the  kidney  should  retain  the  amount  of  sugar  present 
normally  in  the  blood,  yet  excrete  that  which  is  in  excess,  is  an 
unsettled  question.  What  seems  to  be  the  most  simple  explan- 
ation is  that  the  normal  0.1  per  cent,  of  sugar  in  the  blood  does 
not  exist  free,  but  is  combined — partly  with  lecithin  as  jecorin, 
partly  with  proteids.  It  is  certain  that  at  least  part  of  the 
sugar  is  so  combined,  but  we  do  not  know  how  much.  If  it  is 
practically  all  combined,  as  many  believe,  we  can  readily  under- 
stand how  the  sugar  combined  with  large  colloidal  molecules 
could  be  retained  by  the  glomerular  membranes,  while  the  exces- 
sive uncombined  sugar  diffused  through  into  the  urine.  How- 
ever, recent  work  by  Asher  and  Rosenfeld  1  throws  considerable 
doubt  on  the  existence  of  blood-sugar  in  a  non-diffusible  com- 
bination. 

2.     NERVOUS  GLYCOSURIA 

The  classical  example  of  glycosuria  due  to  nervous  impulses 
is  that  discovered  by  Claude  Bernard,  who  found  that  a  minute 
puncture  of  the  floor  of  the  fourth  ventricle,  between  the  roots 
of  origin  of  the  eighth  and  tenth  pairs  of  nerves,  causes  glyco- 
suria. This  glycosuria  begins  in  about  an  hour  after  the  punc- 
ture (piqdre)  is  made,  and  lasts  only  as  long  as  glycogen  remains 
in  the  liver,  for  this  form  of  diabetes  depends  upon  the  rapid 
conversion  of  the  glycogen  of  the  liver  into  sugar.  Because  of 
this  excessive  liberation  of  sugar,  the  blood  contains  more  than 
the  normal  amount  (hyperglycemia),  and  the  excess  escapes 
through  the  kidneys.  If  the  animal  has  been  starved  and  exer- 
cised, so  that  the  glycogen  in  the  liver  is  reduced  to  a  minimum, 
no  glycosuria  is  produced.  All  of  the  excess  of  sugar  comes 
from  the  liver,  for  if  the  hepatic  vessels  are  first  ligated,  no  gly- 
cosuria results  from  puncture. 

This  "diabetic"  or  " glycogenic  center"  seems  to  exist  in  all 
varieties  of  animals,  and  in  man  chronic  glycosuria  has  been 
observed  as  a  result  of  tumors  or  other  lesions  involving  this 
1  Cent.  f.  Physiol.,  1905  (19),  449. 


520  DIABETES 

part  of  the  brain.  Glycosuria  results  from  irritation,  not  from 
destruction  of  the  center.  Undoubtedly  the  glycogenic  center 
has  an  important  function  in  regulating  glycogen  deposition  in 
the  liver.  That  it  exercises  this  function  through  nervous 
impulses  passing  directly  from  the  brain  to  the  liver,  has  been 
conclusively  shown  by  experimentally  severing  various  parts  of 
the  nervous  system  in  animals  whose  diabetic  centers  have  been 
punctured.  If  the  vagus  is  cut,  stimulation  of  its  central  end 
causes  glycosuria,  indicating  that  the  afferent  impulses  travel 
through  this  nerve,  and  glycosuria  has  been  observed  in  persons 
with  tumors  pressing  upon  the  vagus.  The  efferent  impulses 
pass  in  the  spinal  cord  from  the  glycogenic  center  to  the  upper 
thoracic  spinal  roots,  and  by  the  rami  communicantes  into  the 
lower  cervical  and  upper  thoracic  sympathetic  ganglia  ;  thence 
by  the  splanchnic  nerves  to  the  liver.  How  the  nervous  im- 
pulses cause  the  discharge  of  sugar  is  unknown,  but  possibly  it  is 
by  some  direct  stimulation  of  the  cells,  as  with  other  secretory 
impulses.  Against  this,  however,  is  the  fact  that  atropin,  which 
paralyzes  all  true  secretory  nerve-endings,  does  not  prevent  gly- 
cosuria from  piqure.  Bernard  thought  that  the  sugar  produc- 
tion was  increased  merely  by  vasodilation,  and  in  favor  of  this 
view  is  the  fact  that  a  fall  of  blood  pressure  decreases  or  pre- 
vents the  glycosuria. 

In  man,  glycosuria  may  result  from  injuries  to  the  head,  pre- 
sumably because  of  irritation  or  stimulation  of  the  glycogenic 
center.  In  many  nervous  diseases  more  or  less  transient  glyco- 
suria may  occur,  and  an  existing  glycosuria  may  be  augmented 
by  nervous  stimuli.  Administration  of  thyroid  extract,  and 
exophthalmic  goiter,  may  cause  glycosuria,  presumably  from 
nervous  stimulation.  Undoubtedly,  many  of  the  drugs  that 
cause  glycosuria  do  so  through  their  stimulation  of  this  center. 

3.     DRUG  GLYCOSURIA 

A.  Phlorhisin  "Diabetes."1 — This  is  by  far  the  best 
known  and  most  studied  instance  of  glycosuria  produced  by  the 
action  of  drugs,  and  offers  many  points  of  particular  interest. 
Phlorhizin  is  a  glucoside,  obtained  from  the  bark  of  apple  and 
pear  trees,  which  may  be  split  into  dextrose  and  phloretin,  the 
latter  causing  the  characteristic  glycosuric  effects.  When  given 
by  mouth  or  subcutaneously  (the  usual  dose  for  dogs  is  1  gram 
per  kilo,  by  mouth,  and  0.3  to  0.5  gram  subcutaneously),  it 

^eeLusk,  Zeit.  f.  Biol.,  1901  (42),  31;  Cramer,  Ergebnisse  der  Physiol., 
1902  (1),  877. 


DRUG  GLYCOSURIA  521 

causes  a  transient  but  marked  glycosuria ;  as  much  as  19  per 
cent,  of  sugar  may  be  present  in  the  urine  of  well-fed  animals, 
and  from  0.3  to  2.5  per  cent,  if  the  animals  are  starving.  The 
way  in  which  phlorhizin  causes  glycosuria  is  not  fully  deter- 
mined. It  has  been  generally  considered  that  it  acts  directly 
upon  the  kidneys,  so  that  they  excrete  sugar  from  the  blood 
until  it  contains  much  less  sugar  than  normal.  That  the  drug 
acts  directly  upon  the  kidney  is  apparently  proved  by  Zuntz's 
experiment,  which  consisted  of  injecting  phlorhizin  into  one 
renal  artery,  with  the  result  that  sugar  appeared  in  the  urine 
from  this  kidney  at  once,  and  considerably  later  in  the  urine 
from  the  other  kidney.  It  would  also  seem  that  the  excretion 
of  sugar  does  not  depend  upon  a  renal  lesion  that  causes  the 
glomerules  to  "  leak  "  sugar,  but  rather  upon  a  direct  secretory 
activity  of  the  kidney,  since  any  disease  or  injury  of  the  renal 
tissue  diminishes  or  prevents  the  glycosuria  following  phlorhizin 
administration,  although  phlorhizin  itself  causes  necrotic  changes 
in  the  renal  epithelium. 

However,  these  views  have  been  vigorously  opposed.  Pavy 
claims  that  the  blood  in  phlorhizin  diabetes  does  not  contain  less 
sugar  than  normal, — indeed,  he  found  that  it  might  contain 
more, — but  his  results  are  in  contradiction  to  those  of  many 
others,  who  have  found  a  decreased  amount  of  sugar  in  the 
blood  (fiypoglycemia)  as  a  characteristic  feature  of  phlorhizin 
diabetes.  Pfliiger  questions  Zuntz's  results  on  the  ground  that 
the  sugar  observed  in  the  urine  might  have  come  from  the 
phlorhizin  itself,  through  splitting,  and  questions  the  justifica- 
tion of  considering  phlorhizin  glycosuria  as  a  special,  peculiar 
form  of  glycosuria,  differing  from  all  other  forms,  which 
depend  upon  a  hyperglycemia. 

After  repeated  doses  of  phlorhizin,  the  glycogen  may  disap- 
pear to  a  large  extent  from  the  liver,  and  also  from  the  muscles, 
but  the  reduction  is  by  no  means  so  marked  as  in  some  other 
forms  of  glycosuria.  Apparently,  phlorhizin  does  not  act  upon 
the  glycogenic  function  of  the  organs,  but  simply  causes  a  drain- 
ing away  of  sugar,  to  replace  which  the  glycogen  is  converted 
into  sugar.  Corroborating  this  view  is  the  fact  that  if  the 
kidneys  are  tied  off,  administration  of  phlorhizin  does  not 
cause  a  rise  in  the  amount  of  sugar  in  the  blood. 

If  an  animal  to  which  phlorhizin  is  being  repeatedly  given  is 
starved,  the  elimination  of  sugar  does  not  cease,  but  continues 
at  a  low  level,  while  at  the  same  time  the  elimination  of  nitro- 
gen is  increased  until  a  maximum  constant  ratio  of  nitrogen  to 
sugar  is  established,  with  the  proportion  of  dextrose  to  nitrogen 


522  DIABETES 

(the  "  D  :  N  ratio  ")  staying  at  3.75  : 1  (Lusk).  In  pancreat- 
ectomized  dogs  the  D  :N  ratio  is  about  2.8  :  1  during  starva- 
tion (Minkowski).  This  and  other  facts  seem  to  indicate  that 
under  these  conditions  sugar  is  formed  from  the  body  proteids. 
This  brings  forward  the  long-contested  question  as  to  the  possi- 
bility of : 

THE  FORMATION  OF   SUGAR  FROM  PROTEIDS1 

In  favor  of  this  source  of  sugar  has  long  been  known  the  fact  that  dia- 
betics, when  kept  for  a  long  period  on  carbohydrate-poor  diet,  excrete 
sugar  in  quantities  out  of  all  proportion  to  the  amount  of  carbohy- 
drate in  the  food.  At  the  same  time  the  amount  of  nitrogenous  elimi- 
nation will  be  found  to  be  excessive,  supporting  the  idea  that  the  sugar 
of  the  urine  may  have  been  derived  from  the  breaking  down  of  proteids. 
If  the  patient  is  kept  for  some  time  on  a  diet  both  free  from  carbohy- 
drates and  poor  in  proteids,  it  will  be  found  that  the  addition  of  proteid 
to  the  diet  causes  at  once  an  increased  elimination  of  sugar  in  the  urine. 
Nor  is  all  this  sugar  derived  from  the  carbohydrate  groups  of  the  pro- 
teid, for,  firstly,  it  may  greatly  exceed  the  amount  of  carbohydrate 
groups  contained  in  the  proteid  ;  and,  secondly,  the  amount  of  sugar 
escaping  in  the  urine  does  not  vary  according  to  the  amount  of  carbo- 
hydrate in  the  proteid  of  the  food  :  e.g.,  casein  is  free  from  carbohydrate 
groups,  but  it  may  cause  more  increase  in  glycosuria  than  does  egg-albu- 
men, which  is  rich  in  carbohydrate  groups. 2 

It  has  been  demonstrated  experimentally  that  carbohydrates  can  be 
formed  from  the  amino-acids  of  the  proteid  molecule.  If  alanin  is 
given  to  diabetics,  it  will  be  found  to  give  rise  to  almost  equivalent  quan- 
tities of  sugar  ;  with  normal  persons  or  animals  this  conversion  of  alanin 
into  sugar  does  not  seem  to  occur.  Similar,  but  somewhat  less  conclu- 
sive evidence  has  been  obtained  that  glycocoll  and  leucin 3  may  also  be 
changed  into  sugar.  Feeding  of  alanin  to  starved  rabbits  may  cause  an 
increase  in  the  glycogen  in  the  liver  ;  and  starved  animals  poisoned  with 
phlorhizin  excrete  more  sugar  when  alanin  is  given  them,4 

Presumably,  therefore,  amino-acids  liberated  from  the  proteids  during 
their  metabolic  decomposition  can  give  rise  to  carbohydrates.  The  steps 
by  which  alanin  might  be  changed  into  dextrose  are  as  follows : 

CH3 
Alanin  is  amino-propionic  acid,     CH  —  NH2,    and  by  substitution  of 

COOH 

an  OH  group  for  the  NH2  group,  a  process  that  may  readily  occur  in 
the  body  through  the  action  of  deamidizing  enzymes  (amidase),  it  is 

1  Literature  by  Langstein,  Ergebnisse der  PhysioL,  1902  (Bd.  1,  Abt.  1),  63  ; 
1904  (Bd.  3,  Abt.  1),  453;  Therman,  Skand.  Arch.  f.  Physiol.,  1905  (17),  1. 

2  See  Therman,  loc.  cit. 

3Mohr  (Zeit.  exp.  Path.  u.  Then,  1906  (2),  463)  has  noted  the  elimination 
of  leucin  fed  to  diabetics,  in  the  form  of  a  polypeptid. 

*See  Almagia  and  Embden,  Hofmeister's  Beitr.,  1905  (7),  298. 


FORMATION  OF  SUGAR  FROM  PROTEWS  AND  FATS  523 

CH3 
changed  into  lactic  acid,     CHOH.          Lactic  acid,  as  can  be  seen  from 


COOH 


the  formulae,  is  closely  related  to  glyceric  aldehyde,  which  in  turn  may 
readily  be  condensed  into  dextrose,  as  follows  : 

CH2OH  CH2OH  CH2OH 

CHOH       +     CHOH      =     (CHOH)4 

CHO  CHO  CHO 

(glyceric  aldehyde)  (dextrose) 

Serin,    oxy-amino-propionic    acid,    also  a  constituent  of  the   proteid 
molecule,  is  even  more  closely  related  to  dextrose,   as  shown   by   its 

CH2-OH 
formula,     CH-NH2. 


COOH 


Extreme  difficulties  exist  in  such  experimental  work,  because  of  the 
numerous  possible  sources  of  error  which  are  introduced  by  the  following 
conditions  :  (1)  More  or  less  glycogen  is  retained  in  the  tissues  during 
starvation  ;  (2)  the  proteids  of  the  foods  contain  preformed  carbohydrate 
radicals  ;  ( 3)  carbohydrates  may  be  formed  from  fats  ;  (4)  proteids  and 
ainmo-acids  may  be  oxidized  in  place  of  carbohydrates,  which  thus 
escape  destruction  and  cause  increased  glycosuria.  This  has  made  most 
of  the  experimental  evidence  on  this  question  of  uncertain  value  ;  con- 
sequently, while  we  find,  in  a  recent  review  by  v.  Noorden,  the  origin 
of  sugar  from  the  proteid  molecule  treated  as  an  established  fact,  at  the 
same  time  Macleod,  in  his  review  of  the  literature,1  states  that  "there  is 
no  unequivocal  evidence,  so  far"  that  glycogen  formation  can  result 
from  feeding  with  proteids  that  contain  no  carbohydrate  group.  How- 
ever, Macleod  also  states  that  by  the  indirect  method  "the  evidence 
undoubtedly  points  to  sugar  formation  from  all  proteids." 


FORMATION  OF  SUGAR  FROM  FATS 

In  starving  animals  with  glycosuria,  or  in  diabetics  on  a  restricted 
diet,  the  amount  of  sugar  eliminated  often  seems  to  be  greater  than  can 
be  accounted  for  by  destruction  of  the  proteid  of  the  food  and  tissues, 
as  measured  by  the  nitrogen  excretion.  It  would,  therefore,  seem  prob- 
able that  sugar  may,  in  these  conditions,  be  formed  from  the  fats.2 
There  is  no  a  priori  reason  why  this  should  not  occur,  but  the  proof  that 
it  does,  occur  seems  to  be  scanty. 

Glycerin  might  readily  form  sugar,  as  follows  : 

1 "  Kecent  Advances  in  Physiology  and  Biochemistry,"  1906. 
2  Not  in  phlorhizin  diabetes,  according  to  Lusk  (loc.  cit.). 


524 


DIABETES 


CH2OH 

CH2OH           CH2OH 

2CHOH      + 

2O     = 

1                       I 
CHOH    -f-    CO            + 

I 

I                       1 

CH2OH 

CHO               CH3OH 

(glycerin) 

(glycerose) 

CH2OH 

CH2OH 

CH2OH 

CHOH      + 

io 

==     (CHOH)3 

CHO 

CH2OH 

CO 

CH2OH 

(levulose) 

(glycerose) 

2H2O 


Administration  of  glycerin  has  been  found  to  increase  the  amount  of 
sugar  in  the  urine  in  glycosuria.  No  direct  evidence  that  the  higher 
fatty  acids  form  carbohydrates  has  yet  been  brought  forward,  but  v. 
Noorden  believes  that  this  must  occur,  since  in  some  cases  of  diabetes 
he  has  found  more  sugar  in  the  urine  than  could  be  accounted  for  by  the 
other  known  sources,  including  glycerin. 

B.  Other  Substances  Causing  Glycosuria. — A  large 
number  of  substances  may  cause  a  greater  or  less  amount  of 
glycosuria,  when  taken  by  mouth.  Presumably  they  act  in 
different  ways.  Some  of  them  may  stimulate  the  glycogenic 
center ;  this  seems  to  be  the  cause  of  the  glycosuria  following 
injections  of  slightly  hypertonic  solutions  of  sodium  salts  (and 
which  can  be  checked  by  calcium  solutions),  for  when  the 
splanchnic  nerves  are  cut  glycosuria  ceases  (Martin  Fischer  l). 
Strychnine,  phosphorus,  arsenic,  uranium  salts,  bichloride  of 
mercury,  carbon  monoxid,  amyl  nitrite,  curare,  chloral,  nitro- 
benzol,  chloroform,  acetone,  ether,  etc.,2  may  all  cause  glyco- 
suria, but  for  most  of  them  the  point  of  attack  has  not  been 
determined.  Probably  some,  like  salt  solution,  and  also  mor- 
phine, attack  chiefly  the  glycogenic  center.  Others,  among 
which  may  be  included  alcohol  and  the  toxins  of  acute  infectious 
diseases,  seem  to  injure  the  pancreas  particularly.  Caffein  and 
diuretin  both  may  cause  glycosuria,  and,  since  the  chief  charac- 
teristic of  each  drug  is  to  cause  polyuria,  it  has  been  thought 
that  they  act  primarily  upon  the  kidney,  like  phlorhizin,  but 
this  has  not  been  finally  established.  Uranium  salts  are  also 
supposed  to  cause  glycosuria  through  direct  action  upon  the  kid- 
ney cells. 

1  Underbill  and  Closson  (Amer.  Jour.  Physiol.,  1906  (15),  321)  consider  the 
glycosuria  due  to  increased  renal  permeability,  because  a  hypoglycemia  is 
observed. 

2 Literature  given  by  Abderhalden  (loe.  ciL). 


PANCREATIC  GLYCOSURIA  525 

Adrenalin  glycosuria,  which  follows  administration  of  active 
preparations  of  the  adrenal  by  any  route,  has  been  discussed 
elsewhere  (see  "Adrenal,"  page  501).  The  most  marked 
effects  follow  intraperitoneal  injection,  apparently  because  of 
direct  action  upon  the  pancreas,  for  minute  quantities  painted 
upon  the  surface  of  the  pancreas  cause  a  prompt  glycosuria 
(Herter  and  Wakemann  !).  Underbill 2  has  found  that  piper- 
idine  produces  similar  effects,  but  also  causes  glycosuria  equally 
well  if  painted  upon  the  spleen,  the  effect  being  prevented  by 
administration  of  oxygen.  He  suggests  that  piperidine,  potas- 
sium cyanide,  ether,  chloroform,  morphine,  strychnine,  curare, 
and  many  other  similar  substances  owe  their  effect  to  an  action 
upon  the  respiratory  center,  causing  dyspnea  and  consequent 
diminution  of  oxidation  of  carbohydrate  material.  Adrenalin 
glycosuria,  however,  is  not  prevented  by  administering  oxygen  ; 
therefore,  it  must  be  considered  as  essentially  different  from  the 
glycosuria  caused  by  the  above-mentioned  chemicals.3 

4.     PANCREATIC  GLYCOSURIA 

This  form  of  glycosuria  is  of  the  greatest  interest,  not  only 
because  it  seems  to  be  most  closely  related  to  human  diabetes, 
but  also  because  it  opens  up  for  consideration  some  of  the 
long  obscure  points  concerning  the  internal  secretion  of  the 
pancreas  and  carbohydrate  metabolism.  Since  the  experiments 
of  v.  Mering  and  Minkowski  in  1889,4  we  have  known  that 
extirpation  of  the  pancreas  results  in  severe  glycosuria,  and 
that  this  depends  upon  the  lack  of  some  internal  secretion  of 
the  pancreas,  and  not  upon  absence  of  the  pancreatic  juice  that 
escapes  into  the  intestine.  This  last  point  was  conclusively 
shown  by  the  fact  that  retention  of  a  small  portion  of  the 
pancreas — from  10  to  20  per  cent,  of  its  original  bulk — 
prevents  the  development  of  glycosuria,  even  when  the  re- 
tained portion  has  been  transplanted  to  another  part  of  the 
body.  The  glycosuria  appears  from  three  to  five  hours  after 
the  operation ;  at  first  profound,  it  decreases  in  amount  as 
the  glycogen  is  lost  from  the  liver,  but -never  disappears,  even 

^wanoff  (Cent  f.  Physiol,  1906  (19),  891)  has  found  that  adrenalin 
increases  the  rate  of  discharge  of  sugar  from  the  isolated,  glycogen-rich  liver, 
through  which  salt  solution  is  being  transfused. 

2  Jour.  Biol.  Chem.,  1905  (1),  113. 

3Glaessner  (Wien.  klin.  Woch.,  1906  (19),  No.  30)  has  observed  transient 
glycosuria  following  severe  over-cooling;  e.  g.,  attempted  drowning.  The 
glycosuria  is  probably  due  to  defective  oxidation. 

4  "  Diabetes  Mellitus  nach  Pankreasexstirpation,"  Leipzig,  1889  :  also  Arch, 
exp.  Path.  u.  Pharm.,  1890  (26),  371. 


526  DIABETES 

if  the  animal  is  starved.  Feeding  of  carbohydrates  increases 
it  greatly,  and  the  greater  part  of  the  sugar  administered  may 
appear  in  the  urine.  Pancreatectomized  dogs  live  at  most  two 
to  three  weeks,  death  being  due  not  so  much  to  the  disturbance 
of  metabolism  as  to  infection  of  the  operation  wounds,  which 
heal  poorly  because  of  the  high  sugar  content  of  the  blood 
(Pfluger). 

While  the  amount  of  glycogen  in  the  liver  and  muscles 
decreases  greatly,  the  amount  of  sugar  in  the  blood  is  increased. 
Instead  of  the  normal  1  part  per  thousand,  as  much  as  7  to  10 
parts  of  sugar  may  be  present  per  thousand  parts  of  blood,  and 
the  glycosuria  is,  as  in  the  case  of  nervous  glycosuria,  dependent 
upon  hyperglycemia  and  consequent  elimination  of  the  excessive 
sugar  by  the  kidneys.  Since  it  has  been  proved  that  absence 
of  the  pancreatic  juice  is  not  responsible  for  the  glycosuria,  the 
only  remaining  explanation  of  this  hyperglycemia  is  that  it  is 
the  result  of  the  loss  of  some  internal  secretion,  or  the  absence 
of  some  direct  action  of  the  pancreas  itself  upon  the  blood 
passing  through  it.  The  following  explanations  suggest  them- 
selves : 

(1)  The  pancreas  may  directly  destroy  sugar  coming  to  it  in 
the  blood. 

(2)  It   may  secrete  an  enzyme  that  destroys  sugar  in  the 
blood. 

(3)  It  may  neutralize  or  destroy  some  toxic  substance  that 
interferes  with  sugar  metabolism. 

(4)  It  may  secrete  some  substance  that  is  itself  necessary  for 
proper  sugar  metabolism  in  the  liver  and  other  tissues  of  the 
body. 

As  to  the  first  possibility,  it  can  only  be  said  that  we  have 
no  evidence  whatever  that  the  pancreas  is  the  site  of  any  con- 
siderable active  sugar  destruction.  Repeated  investigations  have 
failed  to  show  that  the  pancreas  has  any  marked  powers  of 
glycolysis,  or  contains  any  particularly  active  glycolytic  enzyme 
as  compared  with  other  organs.  That  the  chief  function  of  the 
pancreas  in  carbohydrate  metabolism  consists  of  furnishing  a 
glycolytic  enzyme  to  the  blood  has  been  completely  disproved. 
The  blood  does  exhibit  some  glycolytic  power,  but  this  is  far  too 
slight  to  account  for  the  daily  destruction  of  several  hundred 
grams  of  sugar,  and,  furthermore,  there  is  every  reason  to 
believe  that  this  destruction  takes  place  in  the  tissues,  and  not 
in  the  blood.  If  the  pancreas  is  removed,  the  glycolytic  power 
of  the  blood  is  not  decreased,  showing  that  it  is  not  derived 
from  the  pancreas,  and  the  blood  of  the  pancreatic  vein  is  no 


THE  INTERNAL  SECRETION  OF  THE  PANCREAS    527 

more  actively  glycolytic  than  the  blood  of  the  general  circu- 
lation. 

While  Tuckett1  and  some  others  have  claimed  that  the 
function  of  the  pancreas  is  to  neutralize  toxic  substances  entering 
the  blood  from  the  alimentary  tract,  or  formed  in  metabolism, 
as  yet  their  results  do  not  seem  to  have  received  general  accept- 
ance. The  demonstration  by  Minkowski  and  v.  Mering  that 
the  blood  of  pancreatectomized  dogs  does  not  contain  sub-1 
stances  causing  glycosuria  in  normal  dogs,  seems  to  still  stand  as 
evidence  that  the  glycosuria  does  not  depend  upon  accumulated 
toxic  substances.  Lombroso2  disproved  the  hypothesis  that 
glycosuria  after  pancreatectomy  is  due  to  absorption  of  toxic 
substances  formed  in  the  intestine  because  of  the  defective 
pancreatic  digestion,  by  the  following  experiment :  The  fluid 
escaping  from  a  pancreatic  fistula  of  one  dog  was  injected  into 
the  duodenum  of  a  pancreatectomized  dog  ;  although  the  diges- 
tion of  the  second  dog  was  much  improved,  the  glycosuria  was 
not  reduced. 

The  Internal  Secretion  of  the  Pancreas. — There 
remains,  consequently,  only  the  hypothesis  that  the  pancreas 
secretes  some  substance  that  directly  or  indirectly  modifies  sugar 
metabolism,  and  to  determine  what  this  substance  might  be  has 
been  the  object  of  many  investigations.  Most  suggestive  of 
the  results  obtained  are  those  of  O.  Cohnheim,  who  discovered 
evidence  that  the  internal  secretion  of  the  pancreas  has  the  func- 
tion of  activating  an  inactive  glycolytic  enzyme  that  is  contained 
in  the  liver,  muscles,  and  other  tissues.  Thus,  he  found  that 
whereas  the  expressed  juice  of  fresh  muscle  tissue,  and  the  juice 
of  fresh  pancreas  tissue,  are  each  alike  possessed  of  but  slight 
glycolytic  properties,  yet  when  a  small  amount  of  the  pancreatic 
extract  is  added  to  the  muscle-juice,  the  mixture  is  capable 
of  rapidly  destroying  dextrose.  Enough  destruction  of  sugar 
occurs  in  these  experiments  to  account  fully  for  the  great 
amount  of  sugar  that  is  daily  destroyed  in  the  human  body.3 
The  products  of  this  glycolysis  are  carbon  dioxide  and  water, 
if  an  abundance  of  oxygen  is  present ;  but  in  the  absence  of 
oxygen,  first  alcohol,  then  lactic  acid,  and  later  oxybutyric 

1  Jour,  of  Physiol.,  1899  (25),  63. 

2  Kef.  in  Biochem.  Centr.,  1903  (1),  346. 

3  Rahel   Hirsch,    independently   of    and   simultaneously  with   Cohnheim, 
observed  that  glycolysis  by  liver  tissue  is  increased  upon  the  addition  of  pan- 
creatic extract.     A  number  of  observers,  especially  Jacoby,  Blumenthal,  Fein- 
schmidt  and  Arnheim,  claim  that  the  liver,  and  possibly  other  organs,  contain 
active  glycolytic  enzymes,  but  it  may  be  that  these  are  active  only  because   of 
the  presence  in  them  of  the  pancreatic  secretion  brought  to  them  in  the  blood. 


528  DIABETES 

acid,  are  formed.  An  important  observation,  in  view  of  our 
knowledge  of  the  ability  of  pancreatectomized  animals  to  utilize 
levulose,  is  that  the  combined  pancreas-muscle  or  pancreas-liver 
extracts  do  not  destroy  levulose.1 

The  activating  substance  may  be  compared  with  the  entero- 
kinase  of  the  intestine,  which  activates  the  inert  trypsinogen  of 
the  pancreatic  juice ;  and  Cohnheim  calls  it  the  "  pancreas  acti- 
vator." It  acts  in  very  small  quantities,  is  not  destroyed  by 
alcohol  or  by  heating  to  boiling,  and  excessive  quantities  prevent 
activation  (similar  to  Ehrlich's  "deviation  of  complement"). 
Although  numerous  objections  to  Cohnheim's  views  have  been 
made,  yet  the  main  fact  that  the  pancreas  produces  an  activator 
substance  for  a  glycolytic  enzyme  contained  in  other  tissues 
seems  to  have  been  safely  established.2 

Defective  GlycogenesiS. — This  discovery  perhaps  ex- 
plains why  the  power  to  utilize  sugar  is  reduced,  but  it  does 
not  by  any  means  explain  all  the  features  of  diabetes  following 
pancreatic  injury.  One  of  the  most  important  characteristics 
of  pancreatic  diabetes  is  the  almost  complete  disappearance  of 
glycogen  from  the  liver,  and,  to  a  less  extent,  from  the  muscles, 
while  at  the  same  time  there  may  be  a  deposition  of  glycogen  in 
excessive  quantities  in  other  tissues  where  it  does  not  normally 
occur  abundantly  (see  "  Glycogenic  Infiltration,"  page  363). 

This  decrease  in  the  glycogen  of  the  liver  occurs  at  a  time 
when  the  blood  contains  much  more  sugar  than  it  does  normally, 
and  indicates  that  the  liver  has  almost  entirely  lost  its  normal 
power  of  converting  all  excessive  sugar  into  glycogen.  On  this 
account  we  cannot  be  completely  satisfied  with  an  explanation 
of  pancreatic  diabetes  that  accounts  merely  for  decreased  destruc- 
tion of  sugar,  as  does  Cohnheim's  pancreas  activator.  We  must 
also  account  for  the  impaired  glycogenesis.  v.  Noorden  seeks  to 
explain  this  defective  formation  of  glycogen  by  the  hypothesis 
that  the  pancreas  furnishes  a  secretion  which  either  favors  the 
polymerization  of  sugar  into  glycogen,  or  else  inhibits  the 
power  of  the  tissues  to  split  up  the  glycogen  that  they  have 
formed.  Of  the  two  possible  errors,  excessive  destruction  and 
faulty  formation  of  glycogen,  he  is  inclined  to  favor  the  latter 
as  the  more  probable,  in  view  of  the  well-known  fact  that  pan- 
createctomized dogs  and  diabetics  can  form  glycogen  out  of 
levulose,  when  they  are  unable  to  form  it  out  of  glucose.  The 
added  fact  that  diabetics  can  frequently  utilize  levulose,  in  spite 
of  the  fact  that  the  glycogen  so  formed  must  later  become  glucose, 

1  Sehrt,  Zeit.  klin.  Med.,  1905  (56),  509. 

2  See  Cohnheim's  recent  publication,  Zeit.  physiol.  Chem.,  1906  (47),  253. 


THEORIES  AS  TO  CAUSE  OF  PANCREATIC  DIABETES  529 

is  used  as  an  argument  that  it  is  not  as  sugar  that  the  cells 
utilize  carbohydrates,  but  as  glycogen.  In  the  words  of  v. 
Noorden,  the  natural  carbohydrate  food  of  the  cell  is  not  glucose, 
but  glycogen. 

Pfliiger  takes,  as  the  more  probable,  the  view  that  it  is  excessive 
conversion  of  glycogen  into  sugar,  rather  than  defective  glyco- 
genesis,  that  is  at  fault.  The  function  of  the  pancreas,  on  this 
basis,  is  the  formation  of  an  anti-enzyme  that  holds  in  check 
the  diastatic  enzyme  of  the  cells.  Pavy  maintains  that  after 
sugar  is  once  built  up  into  glycogen  it  goes  on  to  form  fats  and 
proteids,  but  does  not  again  break  down  into  sugar  under 
normal  conditions.  This  view,  in  direct  opposition  to  Bernard's 
theories  of  carbohydrate  metabolism,  is  not  generally  accepted. 

Theories  as  to  the  Cause  of  Pancreatic  Diabetes — 
With  the  existing  confusion  and  difference  of  opinion  concern- 
ing the  importance  of  defective  glycogen  formation  in  diabetes, 
it  is  impossible  to  give  an  exact  or  clear  idea  concerning  the 
role  of  the  pancreas  in  diabetes.  Certainly,  after  pancreas  ex- 
tirpation the  liver  does  not  entirely  lose  its  power  to  form 
glycogen,  for  some  glycogen  may  be  still  present  in  the  liver 
after  the  most  protracted  glycosuria.  Neither  does  defective 
glycogenesis  explain  why  the  blood  of  starving  pancreatec- 
tomized  animals  contains  excessive  quantities  of  sugar.  This 
last  fact  speaks  rather  in  favor  of  excessive  breaking  down  of 
the  glycogen,  analogous  to  the  glycosuria  following  puncture  of 
the  medulla.  Possibly,  either  the  glycolytic  ferments  or  the 
glycogen  are  normally  so  combined  in  the  cells  that  they  cannot 
freely  act  or  be  acted  upon  to  form  sugar,  which  combined  con- 
dition ceases  to  exist  in  the  absence  of  the  internal  secretion  of 
the  pancreas.  This  is,  of  course,  purely  hypothetical. 

There  can  be  no  doubt  that  the  tissue-cells  of  pancreatec- 
tomized  animals  have  lost  their  power  to  utilize  sugar,  leaving 
out  of  the  question  whether  this  is  due  to  abnormal  glycogenesis 
or  to  loss  of  glycolytic  power.  Feeding  of  carbohydrate  food 
causes  immediately  an  increase  in  the  amount  of  sugar  excretion, 
and  usually  the  greater  part  of  the  sugar  appears  again  in  the 
urine,  showing  that  it  has  passed  through  the  body  unutilized. 
Levulose  alone  seems  to  be  fairly  utilized  under  these  conditions. 
This  failure  to  use  the  sugar  is  not  due  to  a  decrease  in  the 
oxidizing  powers  of  the  cells,  for  other  substances  seem  to  be 
oxidized  with  quite  normal  activity.  Lactic  acid,  inosite,  man- 
nite,  benzol,  and  many  other  substances,  when  given  by  mouth, 
are  oxidized  as  in  normal  animals.  The  respiratory  quotient  is 
affected  only  as  far  as  the  loss  of  carbohydrates  reduces  the  sum 

34 


530  DIABETES 

total  of  oxidation  that  is  going  on.  Proteicls  and  fats  are 
oxidized  to  a  large  extent,  although  the  appearance  of  volatile 
fatty  acids  in  the  urine  in  advanced  diabetes  may  be  taken  to 
indicate  that  the  oxidation  is  not  up  to  normal  standards.  O. 
Baumgarten1  has  recently  demonstrated  that  certain  partly 
oxidized  carbohydrates  can  be  oxidized  completely  in  the  tissues 
of  pancreatectomized  dogs.  The  bodies  examined  were  d-gluconic 
acid,  c?-saccharic  acid,  mucic  acid,  glycuronic  acid,  glycosamin 
hydrochloride,  succinic  acid,  c/-tartaric  acid,  salicylic  aldehyde, 
and  vanillin.  The  relation  of  some  of  these  bodies  to  glucose 
is  shown  by  the  following  formula? : 

CH2OH  CH2OH  COOH  COOH 

(CHOH)4  (CHOH)4  (CHOH)4  (CHOH), 

CHO  COOH  CHO  COOH 

(d-glucose)  (d-gluconic  (d-glycuronic          (d-saccharic 

acid)  acid)  acid) 

These  experiments  indicate  that  the  diabetic  organism  can 
oxidize  sugars  after  a  start  has  been  made  on  the  oxidation,  and, 
as  it  is  unable  to  oxidize  them  before  this  first  step  has  been 
performed,  it  is  a  fair  assumption  that  the  difficulty  lies  with 
the  first  attack  on  the  sugar  molecule.  Baumgarten  believes 
that  a  "fermentative  splitting  of  the  sugar  molecule  must 
precede  oxidation  of  the  carbohydrates,  which  splitting  is  more 
or  less  incomplete  in  diabetes."  On  the  other  hand,  we  have 
evidence  that  diabetics  are  not  totally  incapable  of  beginning 
the  oxidation  of  glucose,  for  if  they  receive  such  substances  as 
are  eliminated  in  the  urine  combined  with  glycuronic  acid  (e.  g., 
camphor,  chloral,  naphthol,  etc.),  they  eliminate  this  glycurouic 
acid  compound  almost  as  abundantly  as  do  normal  individuals. 
Indeed,  glycuronic  acid  is  frequently  eliminated  in  diabetes, 
even  without  the  presence  of  the  above-mentioned  combining 
bodies ;  and  sometimes  it  may  be  found  in  the  urine  even  when, 
through  careful  dieting,  the  excretion  of  sugar  has  ceased.  As 
'  glycuronic  acid  represents  merely  the  result  of  the  first  step  of 
oxidation  of  glucose,  as  shown  by  the  formulae  given  above,  it- 
would  seem  that  the  first  step  of  sugar  oxidation  can  be  accom- 
plished in  diabetes,  and  that  the  fault  lies  rather  with  the 
subsequent  splitting  of  the  molecule.  This  view  does  not 
harmonize  with  Baumgarten's  experiments,  and  the  disagree- 
ment has  yet  to  be  explained.  In  any  case,  however,  experi- 
menters are  well  agreed  that  the  difficulty  in  diabetes  lies  in  the 

1  Zeit.  exp.  Path.  u.  Ther.,  1905  (2),  53. 


HUMAN  DIABETES  531 

splitting  of  the  long  hexose  chain,  rather  than  in  the  oxidation 
processes  themselves. 

HUMAN  DIABETES 

Diabetes,  being  characterized  by  a  long-continued  glycosuria, 
we  may  imagine  it  to  be  due  to  any  or  all  of  the  causes  mentioned 
in  the  preceding  discussion.  As  a  matter  of  fact,  however,  it 
is  in  most  cases  related  more  closely  to  pancreatic  glycosuria 
than  to  the  other  forms. 

Diabetes  from  an  increased  permeability  of  the  kidneys,  analogous 
to  phlorhizin  glycosuria,  has  not  been  established  as  a  definite 
condition  in  man,  although  its  existence  has  been  suspected  and 
urged  more  than  once.  On  the  other  hand,  the  development  in 
a  diabetic  of  renal  lesions,  especially  chronic  interstitial 
nephritis,  may  greatly  reduce  the  excretion  of  sugar  in  the 
urine. 

True  diabetes  from  excessive  consumption  of  carbohydrates  is, 
of  course,  out  of  the  question,  but  often  in  its  earliest  stages 
diabetes  presents  the  symptom  of  glycosuria  only  when  excessive 
quantities  of  carbohydrates  are  taken  in  the  food.  Diabetes 
from  overproduction  of  sugar  in  the  body  is  also  unknown — 
the  abnormally  great  formation  of  sugar  from  proteids  (and 
probably  from  fats)  that  occurs  in  diabetes,  is  secondary  to  the 
loss  of  sugar  and  not  primary. 

True  diabetes  may,  however,  result  from  purely  nervous 
causes,  exactly  analogous  to  glycosuria  following  Bernard's 
puncture  of  the  medulla.  This  has  been  observed  in  a  few 
instances  in  persons  suffering  from  tumors,  hemorrhages,  soften- 
ing, etc.,  in  the  vicinity  of  the  diabetic  center.  There  is  also 
much  evidence  that  in  diabetes  generally  the  nervous  system 
plays  an  active  part,  and  nervous  shock,  depression,  etc.,  are 
known  to  exert  an  unfavorable  influence  on  the  course  of 
diabetes.  The  favorable  therapeutic  effects  obtained  in  diabetes 
with  opium  have  been  ascribed  to  the  reduction  of  nervous 
excitability.1  It  is  quite  probable  that  the  discharge  of  glyco- 
gen  from  the  liver,  which  is  so  marked  a  feature  of  diabetes,  is 
brought  about  by  nervous  stimuli,  similar  to  those  which  empty 
the  liver  of  glycogen  when  the  glycogenic  center  is  irritated. 
These  stimuli  presumably  arise  from  the  tissues,  which  are  in  a 
condition  of  sugar  starvation  because  of  their  inability  to 
utilize  sugar,  and,  therefore,  send  stimuli  calling  for  more  sugar 
to  the  glycogen  storehouses. 

1  See  Meyer,  Zeit.  exp.  Path.  u.  Ther.,  1906  (3),  58. 


532  DIABETES 

But,  in  its  cardinal  features,  human  diabetes  most  generally 
resembles  pancreatie  diabetes,  and  in  a  large  proportion  of  the 
cases  lesions  of  the  pancreas  are  found  present.  These  are  not 
always  marked,  however,  and  they  are  by  no  means  constant. 
Opie,  in  particular,  has  brought  forward  evidence  that  diabetes 
is  frequently  associated  with  lesions  of  the  islands  of  Langer- 
hans,  whereas  extensive  lesions  of  the  pancreas  which  do  not 
involve  the  islands  (e.  y.,  sclerosis  and  atrophy  following 
occlusion  of  the  pancreatic  duct)  do  not  cause  diabetes.  This, 
of  course,  suggests  that  the  islands  of  Langerhans  produce  the 
internal  secretion  of  the  pancreas  that  has  to  do  with  sugar 
metabolism.  The  full  evidence  on  this  point  will  be  found  in 
Opie's  work  on  "  Diseases  of  the  Pancreas."  However,  there 
occur  many  cases  of  diabetes  in  which  no  anatomical  changes 
whatever  can  be  found  in  the  pancreas,  and  others  in  which  the 
lesions  in  the  parenchyma  far  outweigh  those  of  the  Langer- 
hans islands.1  Still  another  fact  of  significance  in  this  connec- 
tion is  that  organotherapy,  by  means  of  pancreas  preparations, 
has  given  no  favorable  results  in  diabetes,  even  when  the 
diabetes  has  been  unquestionably  of  pancreatic  origin.2 

We  must,  therefore,  recognize  the  probability  that  pancreatic 
disease  is  not  the  sole  cause  of  diabetes  and  that  the  importance 
of  the  islands  of  Langerhans  is  not  finally  established,  while  at 
the  same  time  recognizing  the  fact  that  failure  to  detect  ana- 
tomical changes  does  not  always  prove  the  absence  of  func- 
tional impairment. 

The  glycosuria,  which  is  the  most  characteristic,  but  by  no 
means  the  sole,  important  feature  of  diabetes,  is  dependent  upon 
hyperglycemia.  The  amount  of  sugar  in  the  blood  is  often 
as  much  as  three  parts  per  thousand,  instead  of  one  part  as  nor- 
mally, and  may  reach  7  to  10  parts;  however,  the  amount  of 
sugar  in  the  urine  does  not  by  any  means  vary  directly  with 
the  amount  in  the  blood.  This  hyperglycemia  is  remarkable  in 
that,  at  least  in  the  advanced  stages  of  diabetes,  it  persists  even 

1  For  the  evidence  against  the  view  that  the  islands  of  Langerhans  are  the 
chief  factor  in   pancreatic  diabetes  see    Herxheimer,  Virchow's  Arch.,  1906 
(183),  228. 

2  Moore,  Edie,  and  Abram   (Biochem.  Jour.,  1906   (1),  28  and  446)  have 
obtained  a  favorable  influence  in  certain  cases  of  diabetes  by  stimulating  the 
pancreas   through  administration    of  secretin  obtained    in   duodenal  extracts. 
Secretin  is  a  secretion  of  the  upper  part  of  the  small   intestine,  which  has 
the  property   of  causing  a  greatly  increased  flow  of  pancreatic  juice.     Pre- 
sumably it  produces  its  effect  in  diabetes  by  increasing  the  internal  secretion 
of  the  pancreas.     Bainbridge  and  Baddard  (Biochem.  Jour.,  1906  (1),  429) 
found   the  secretin   content   of  the   intestinal    mucosa  greatly  decreased   in 
human    diabetes,    although   unable   to   obtain   favorable   clinical   results  by 
administration  of  duodenal  extracts. 


HUMAN  DIABETES  533 

when  the  patient  is  receiving  no  carbohydrate  whatever  in  the 
food.  In  the  early  stages  glycosuria  may  appear  only  after  the 
taking  of  carbohydrates,  so  that  it  may  be  entirely  suppressed 
by  proper  diet.  Later,  however,  as  the  power  to  utilize  sugar 
becomes  still  more  impaired,  the  demand  of  the  tissues  for  sugar 
becomes  so  great  that  carbohydrates  are  formed  in  large 
amounts  from  proteids,  and  perhaps  also  from  fats.  At  the 
same  time  the  sugar  given  by  mouth  passes  unappropriated 
through  the  tissues,  and  the  greater  part  of  it,  sometimes  all, 
reappears  unchanged  in  the  urine.  As  with  experimental  pan- 
creatic diabetes,  the  power  to  utilize  levulose  is  retained  longer 
than  for  dextrose,  but  eventually  even  the  levulose  is  largely 
lost,  after  being  partly  converted  into  glycogen. 

The  power  to  oxidize  substances  other  than  dextrose  is  at 
first  apparently  unimpaired,  but  later  the  general  oxidative 
capacity  is  reduced,  and  we  find  large  quantities  of  uuderoxid- 
ized  products  of  metabolism  appearing  in  the  urine,  especially 
the  "  acetone  bodies."  The  presence  of  these  organic  acids  in 
the  blood  in  large  amounts  leads  to  diabetic  coma,  which  is  in 
most  respects  an  aeid  intoxication.  (This  matter  is  discussed 
fully  under  the  topic  of  "  Acid  Intoxication/'  Chap,  xviii.) 
Undoubtedly,  other  toxic  substances  also  accumulate,  and  con- 
stitute an  important,  if  subordinate,  cause  of  the  toxic  manifes- 
tations of  the  disease.  Failure  of  oxidation  of  fats  is  perhaps 
responsible  for  the  frequently  observed  accumulation  of  large 
quantities  of  fat  in  the  blood — lipemia.  (Discussed  under 
"  Fatty  Metamorphosis,"  page  344.)  The  failure  of  oxidation 
of  sugar  is  so  marked  that  it  is  impossible  to  cause  the  glyco- 
suria to  be  reduced  greatly,  at  least  in  severe  cases,  by  hard 
muscular  exercise.  Thus,  a  patient  who  is  excreting  sugar  on 
a  carbohydrate-free  diet  may  climb  a  mountain  or  do  other 
severe  work  which  requires  normally  the  burning  up  of  80  to 
100  grams  of  carbohydrate,  and  yet  continue  to  excrete  nearly 
or  quite  as  much  sugar  as  he  did  before.  This  indicates  that 
all  the  energy  available  for  the  diabetic  must  come  from  fats 
and  proteids,  because  of  the  inability  to  utilize  sugar  under  even 
the  most  extreme  conditions. 

In  any  case,  the  pathology  of  human  diabetes  usually  re- 
sembles that  of  diabetes  following  experimental  pancreatectomy 
in  its  chief  features,  and  the  problems  are  quite  the  same  as 
those  which  have  already  been  discussed  in  connection  with  the 
experimental  disease.  We  are  entirely  uninformed  as  to  the 
parts  played  by  defective  glycogenesis  and  by  defective  oxida- 
tion of  sugar,  independent  of  a  preliminary  conversion  into 


534  DIABETES 

glycogen.  Furthermore,  in  the  large  majority  of  cases  we  do 
not  know  the  cause  of  such  pancreatic  lesions  as  may  be  found 
at  autopsy.  Sometimes  there  is  evidently  a  chronic  inflamma- 
tory process  in  the  gland  resulting  from  occlusion  or  infection 
of  its  duct,  but  usually  this  form  of  pancreatitis  does  not 
involve  seriously  the  islands  of  Langerhans  or  cause  diabetes. 
In  the  majority  of  the  cases  of  diabetes  in  which  pancreatic 
lesions  are  found  the  islands  seem  to  be  more  affected  than  the 
other  tissues, — indeed,  they  often  appear  to  be  specifically 
affected, — and  the  cause  of  this  attack  upon  the  islands  is  quite 
unknown. 

The  metabolic  processes  in  diabetes  seem  also  to  be  disturbed 
in  quite  the  same  way  as  after  pancreatectomy,  except  in  respect 
to  the  interference  with  digestion  in  the  pancreatectomized 
animals  because  of  the  total  absence  of  the  pancreatic  juice. 
(However,  in  some  cases  of  human  diabetes  the  pancreatic 
changes  are  so  extensive  as  to  interfere  with  the  secretion  of 
pancreatic  juice.)  Utilization  of  proteids  and  fats  remains  nor- 
mal for  some  time,  with  excessive  destruction  of  both  to  com- 
pensate for  the  lack  of  carbohydrate  combustion,  and  a  conse- 
quent increased  elimination  of  nitrogen  in  the  urine.  Indeed, 
the  amount  of  nitrogen  eliminated  may  exceed  that  taken  in  with 
the  food,  because  of  the  wasting  in  the  tissues.  This  loss  is 
commonly,  although  without  conclusive  proof,  attributed  to  the 
action  of  poisonous  substances  upon  the  tissues,  and  called 
"  toxogenic  proteid  disintegration."  Associated  with  this  tissue 
destruction  is  the  presence  in  the  urine  of  excessive  quantities 
of  purin  bodies  derived  from  the  tissues  (endogenous  purin 
bodies).  If  all  carbohydrates  are  eliminated  from  the  diet, 
excretion  of  sugar  may  continue,  indicating  that  sugar  may  be 
formed  from  proteids  and  fats.  According  to  v.  Noorden,  syn- 
thesis of  fat  from  carbohydrates  is  also  impaired  in  most  cases 
of  diabetes,  leading  to  wasting ;  but  in  some  cases  the  synthesis 
of  fat  is  not  impaired,  and  in  this  event  the  fat  tissues,  being 
richly  bathed  with  carbohydrates,  build  up  excessive  quantities 
of  fat,  leading  to  obesity.  At  first  this  formation  of  fat  from 
the  sugar  may  prevent  glycosuria,  but  later  the  glycosuria 
appears,  and  we  have  the  common  form  of  "  diabetes  in  the 
obese."  l 

Loss  of  sugar  and  its  consequences  are  not  the  only  abnor- 
malities from  which  diabetics  suffer.  The  excessive  quantity  of 

1  According  to  Thoinotand  Delamare  (Presse  He'd.,  1904  (12),  491),  pancre- 
atic lesions  are  not  present  in  cases  of  diabetes  in  the  obese  nor  in  nervous 
diabetes. 


HUMAN  DIABETES  535 

sugar  in  the  blood  seems  to  exercise  a  deleterious  effect  upon  the 
tissues  of  the  body,  which  is  especially  seen  in  the  failure  of 
repair  in  wounds.  Slight  injuries  often  lead  to  extensive  tissue 
necrosis  and  gangrene.  That  this  tendency  to  tissue  disintegra- 
tion and  necrosis  depends  upon  the  hyperglycemia  seems  prob- 
able, because  measures  that  are  taken  to  reduce  the  amount  of 
sugar  in  the  blood  exercise  a  favorable  influence  upon  the  tissue 
changes  ;  however,  we  cannot  be  sure  that  unknown  toxic  mate- 
rials are  not  also  being  reduced  pari  passu  with  the  sugar. 
Furthermore,  the  amount  of  necrosis,  gangrene,  etc.,  of  diabetes 
does  not  seem  to  bear  a  direct  relation  to  the  intensity  of  the 
hyperglycemia.  However,  there  is  no  doubt  that  measures 
taken  to  keep  down  the  amount  of  sugar  in  the  blood  and  urine 
give  diabetic  patients  the  greatest  freedom  from  complications 
and  the  longest  duration  of  life,  whether  or  not  the  sugar  itself 
is  the  cause  of  their  symptoms  and  sufferings. 

v.  Kossa  has  shown  that  all  varieties  of  sugar  are  toxic,  caus- 
ing symptoms  in  many  respects  similar  to  those  of  diabetes 
when  injected  subcutaneously  in  doses  of  1  per  cent,  (cane-sugar) 
of  the  body  weight.  Smaller  doses,  long  continued,  cause  ex- 
treme emaciation  with  much  loss  of  nitrogen  and  the  develop- 
ment of  nephritis.  Albertoni  observed  increased  heart  action 
following  injections  of  sugar,  and  Harley  found  that  glucose 
injections  caused  the  appearance  of  acetone  bodies  in  the 
blood.1  Scott 2  has  claimed  that  glucose  injections  cause  an 
increased  elimination  of  nitrogen  in  forms  other  than  urea,  due 
to  abnormal  metabolism ;  this  observation  could  not  be  cor- 
roborated by  Underbill  and  Closson.3 

Possibly  increased  osmotic  pressure  of  the  blood,  because  of 
the  excess  of  sugar,  plays  an  important  role  in  the  tissue 
changes ;  but  this  factor  seems  not  to  have  been  investigated, 
except  for  Pusey's  experiments,4  which  suggest  the  importance 
of  osmotic  pressure  in  the  production  of  cataract,  which  is  such 
a  common  result  of  diabetes. 

Sweet5  has  found  that  removal  of  the  pancreas  causes  (in 
dogs)  complete  loss  of  bactericidal  power,  probably  because  of 
loss  of  bactericidal  complement.  The  hemolytic  power  for  foreign 
corpuscles  is  also  greatly  reduced  through  this  loss  of  com- 
plement. It  is  quite  possible  that  some  similar  impairment  of 
bactericidal  power  explains  the  tendency  to  infection  in  diabetes. 

1  See  Pfliiger,  Pfluger's  Arch.,  1903  (96),  376. 

2  Jour,  of  PhysioL,  1902  (28),  107. 

3  Jour.  Biol.  Chem.,  1906  (2),  117. 
*Arch.  of  Ophthalmology,  1904  (33),  128. 
5  Jour.  Med.  Kesearch,  1903  (10),  255. 


536  DIABETES 

11  Bronzed  Diabetes," — In  this  condition  there  appears  a  wide-spread 
deposition  of  an  iron-containing  pigment  in  the  tissues  and  organs  of 
the  body,  associated  with  the  accumulation  of  an  iron-free  pigment  in 
places  where  normally  pigment  is  found  in  smaller  amounts.  This  sub- 
ject is  discussed  under  "Pigmentation"  (page  404).  The  diabetes  is 
due  to  an  interstitial  pancreatitis,  and  must  be  considered  as  secondary  to 
the  disease,  hemochromatosis,  and  not  primary.1  The  cause  of  the  dis- 
ease is  unknown. 


CHRONIC  POLYURIA 

"  Diabetes  insipidus,''  which  in  some  instances  terminates  in  diabetes 
mellitus,  but  most  generally  seems  to  be  quite  distinct  from  true  diabetes, 
presents  little  for  consideration  from  the  chemical  side.  Most  striking, 
but  by  no  means  constant  or  characteristic,  is  the  occurrence  of  inosite 
in  the  urine,  sometimes  in  considerable  quantities.  Inosite,  which 
occurs  normally  in  the  muscles,  liver,  spleen,  kidneys,  and  other  organs,'2 
has  been  frequently  found  in  the  urine  in  both  normal  and  pathological 
conditions.  Although  its  empirical  formula,  C6H12O6,  is  identical  with 
that  of  the  hexoses,  yet  it  is  a  benzene  derivative  (Maquenne),  having 
the  following  formula : 

XCHOH  —  CHOHL 

CHOH(  )CHOH. 

XCHOH  —  CHOH/ 

The  normal  constituents  of  the  urine  are  generally  increased  in  total 
amount,  as  if  washed  out  with  the  excessive  elimination  of  water.  Con- 
sequently patients  with  this  disease  suffer  from  thirst  and  hunger,  and 
drink  and  eat  abnormally  great  quantities.  Meyer3  states  that  the  con- 
centration of  the  urine  tends  to  remain  uniform,  and  that  the  amount  of 
water  is  varied  to  regulate  the  concentration  according  to  the  amount  of 
solids  that  are  eliminated. 

The  etiology  of  the  disease  is  unknown,  but  is  probably  various. 
Often  it  seems  to  be  hereditary,  but  sometimes  has  been  found  associated 
with  lesions  in  the  pons,  medulla,  or  cerebellum,  which  agrees  with  the 
observation  of  Bernard  that  experimental  injuries  of  these  parts  may  be 
followed  by  polyuria  without  glycosuria.  In  any  case  the  increased  flow 
of  urine  seems  to  be  due  to  a  dilatation  of  the  vessels  of  the  kidney, 
without  increased  arterial  pressure  ;4  indeed,  abnormally  low  blood  pres- 
sure is  often  present.  Presumably  this  vasodilatation  depends  upon 
nervous  influences  ;  a  similar  condition  may  be  produced  in  animals  by 
cutting  the  renal  nerves.5 

1  See  Opie,  Jour.  Exper.  Med.,  1899  (4),  279;  Anschiitz,  Dent.  Arch,  klin, 
Med.,  1899  (62),  411 ;  Hess  and  Zurhelle,  Zeit.  klin.  Med.,  1905  (57),  344. 

2  See  Meillere,  "  Inosurie.  Recherche  de  1' inosite  dans  les  tissus,  les  secre- 
tions et  les  excretions."    Paris,  1906. 

3 Dent.  Arch.  klin.  Med.,  1905  (83),  1. 

4  Review  and  literature  by  R.  Schmidt,  Wien.  klin.  Woch.,  1905  (18),  1112. 

5  Tallqvist  (Zeit.  klin.  Med.,  1903  (49),  181)  on  the  basis  of  a  study  of  the 
conditions  of  metabolism,  suggests  that  the  polyuria  of  diabetes  insipidus  may 
be  due  to  a  defective  resorption  of  water  in  the  renal  tubules. 


INDEX 


NOTE.— The  numbers  printed  in  bold-face  type  refer  to  pages  upon  which 
the  topic  is  specifically  discussed. 


ABRIN,  166,  196 

Absorption  affinity,  371 

Acetic  acid,  164,  479 

Aceto-acetic  acid,  452 

Acetone,  452-459,  476 

Acetonemia,  533.  See  Acid  intoxication. 

Acetonuria.     See  Acid  intoxication. 

Acid  intoxication,  440,  451-459 

Acidosis.     See  Acid  intoxication. 

Acromegaly,  496-498 

Actinomyces,  108 

Activation  of  enzymes,  70 

Acute  yellow  atrophy  of  liver,  98,  99, 

443-450 
Adaptation  in  bacteria,  111 

to  heat,  311 
Addison's  disease,  397,  498-500 

melanin  in,  397 
Adenase,  88,  507 
Adenin,  504,  506,  513,  515 
Adipocere,  342-344 
Adipose  effusions,  303 
Adiposis  dolorosa,  421 
Adrenalin,  400,  498-502 

arterial  degeneration  from,  501 

glycosuria,  501,  525 
Adrenals,  498-502 
Aethalium  septicum,  208 
Agglutination,  148-152,  175,  176,  202 

physics  of,  150 

thrombi,  194,  202 
Agglutinins,  148-152,  180,  194,  270 

cholera,  140 

typhoid,  140 
Agglutinogen,  148 
Agglutinoid,  149 
Air  embolism,  272 
Alanin,  20,  448,  522 
Albinism,  393 
Albumin,  24,  297,  298,  412 

serum,  249,  250 

toxic,  169,  196 
Albumose.     See  Proteose. 
Albumosuria,  232,  414,  467 

myelopathic,  427-430 
Alcoholism,  344 
Aldehydase,  78,  81,  98 


Alimentary  glycosuria,  516-518 
Alkalescence  of  blood,  240-242,  251 , 

253,  255,  261,  372,  375,  436,  437, 

440,  460 

Alkaptonuria,  397,  474,  475 
Allantoin,  299,  509 
Alloxan,  509 
Alloxuric  bodies,  504 
Amanita,  168 
Amanitotoxin,  169 
Amblyopia,  495 
Amboceptor,  145-147 
Ameba  coli,  130 
Amebse,  artificial,  220-224 
Ameboid  motion,  208-229 
Amibodiastase,  216 
Amidase,  522 
Amino-acids,  20-24,  450,  467,  475 

of  tumors,  413 
Amino-oxybutyric  acid,  454 
Aminovalerianic  acid,  20 
Ammoniomagnesium    phosphate    cal- 
culi, 383, 388 
Ammonium  carbamate,  434 

salts,  toxicity,  434 
Amylase,  417 
Amyloid,  347-352,  353 

chemistry  of,  348-350 

local,  352 

origin  of,  351 

staining  reactions,  350 
Anemia,  248-255 

bothriocephalus,  133 

local,  310 

pernicious,  252-255,  265 

secondary,  248-250 
Anemic  necrosis,  308,  310.  See  Infants. 
Anesthesia,  59, 457 
Animal  parasites,  chemistry  of,    129- 

135 

Ankylostoma.     See  Uncinaria. 
Anthracosis,  392 
Anticatalase,  77, 
Anticomplement,  204 
Anti-enzymes,  72-74,  90,  94,  97,  230, 
310 

bacterial,  147 

537 


538 


INDEX 


Antihemolysins,  193 

Antikinase,  73,  135 

Antiricin,  167 

Antiseptics,  effects  on  enzymes,  62,  69 

Antitoxin,  137-143 

chemical  nature  of,  139-142 

eel  serum,  186 

hay  fever,  169 

spider  poison,  181 
Antitrypsin,  73,  74,  134,  135,  324 
Antivenin,  178,  199 
Ant  poison,  182 
Arachidic  acid,  424 
Arachnolysin,  181 
Arginin,  21,  98,  448,  476 
Arsenic,  287 

immunity  against,  157,  159,  160 
Arterial  degeneration  from  adrenalin, 

501 

Arthritis,  rheumatoid,  459 
Ascaris,  134 
Ascites,  295,  297,  298,  299 

adiposus,  304 

autolysis  in,  94 

cancerous,  412 
Aspartic  acid,  20,  448 
Assimilation  limit  of  sugars,  517 
Atheroma,  345,  501 
Atrophy,  93 

acute  yellow,  98,  99,  443-450 
Autocytotoxins,  206 
Autodigestion,  86.     See  Autolysis. 
Auto-intoxication,  431-482 

gastro-intestinal,  464 
Autolysis,  86-103,  118,  230-233,  234, 
256,  258,  266,  267,  270,  273,  274, 
299-330,  337-341,  375,  394,  412, 
418 

in  relation  to  infection,  100 
Auxanographic  method,  110,  471 

BACILLUS  aerogenes   capsulatus,  254, 

273,  326 
anthracis,  107,  108,   110,  112,  113, 

127,  128,  147,  229 
botulinus,  120,  122 
coli,   106,  108,  112,  114,  126,  268, 
306,  326,  379,  472 

enzymes  of,  95 
diphtheria,  120,  128 
dysenteriae,  114 
enteritidis,  117 
pyocyaneus,  110,  114,  120,  127,  128, 

194,  195,  202/231,268 
tetani,  120 

tuberculosis,  107,  108,  126,147,  268, 
319,  320 

enzymes  of,  98 

fats  of,  107,  108 
typhosus,  133,   114,   124,   126,   155, 

194,  195,  202,  379 


Bacteria,  adaptation  in,  111 

autolysis  of,  91 

chemistry  of,  104-128 

chemotaxis  of,  105 

fats  of,  107,  108 

hemolysis  by,  194-196 
Bacterial    proteids,    poisonous,    125- 

127 

Bactericidal  action  of  autolytic  prod- 
ucts, 100,  114 

fluids,  300 

power  of  blood,  241, 261,  535 

serum,  144-148,  177 
Bacteriolysis,  144 
Barium,  159 
Bee  poison,  182 
Bence- Jones  proteid,  427-430 
Benzoic  acid,  163,  473 
Betain,  118-120 

Beta-oxybutyric  acid,  452-456,  460 
Bezoar  stones,  389 
Bile,  211 

acids,  159,  164 

pigments,  376-380,  405-410 

salts,  323,  380 

toxicity  of,  407 
Biliary  calculi,  376-380 
Bilicyanin,  377 
Bilifuscin,  377 
Bilihumin,  377,  379 
Bilirubin,   244,   313,   401,   405,    408, 

449 

Bilirubin-calcium  calculi,  377 
Biliverdin,  377,  405 
Biurates,  391 
Blastomyces,  227 
Blister  fluid,  303,  463 
Blood,  alkalescence  of,  240-242,  251, 
253,  255,  261,  372,  375,  436,  437, 
440,  460 

bactericidal  power  of,  241,  261,  535 

coagulation   of,   185,  243,   246,  256, 
263-269,  449 

composition  of,  238-242 

electrolytes  of,  240 

freezing-point  of,  435 

pigments,  400-405 

platelets,  239,  264,  269 

viscosity  of,  240,  262 
Bothriocephalus.      See  Dibothnoceph- 

alus. 

Bronchiectasis,  234,  345 
Bronchitis,  234,  378 
Bronzed  diabetes,  404,  536 
Brown  atrophy,  399,  404 
Bufonin,  182 
Bufotalin,  182 
Bums,  215,  303 

poisons  produced  in,  461-463 
Butter  cyste,  425 
Butyric  acid,  425,  457,  479 


INDEX 


539 


CACHEXIA,  233,  243,  249,  297,  299 

acidosis  in,  457-459 

cancer,  418,  458 
Cadaverin,  118,  476,  478 
Cafiein,  505 
Caisson  disease,  272 
Calcification,  364-375 

calcium  soaps  in,  370 

iron  in,  365 

metastatic,  367 

phosphoric  acid  in,  370 
Calcium,  258,  331,  420,  425 

carbonate  calculi,  383 

in  fibrin  formation,  265 

metabolism,  497 

oxalate  calculi,  382,  387 

salts,  376-380 

soaps,  323,  342,  346,  370,  391,  421, 

425 

Calcospherites,  366 
Calculi,  375-392 

ammonio-magnesium  phosphate, 
383,  388 

biliary,  376-380 

bilirubin-calcium,  377 

calcium  carbonate,  383 
oxalate,  382,  387 

cholesterin,  376-380,  385 

cystin,  384 

fibrin,  385 

fusible,  383 

indigo,  384 

metamorphosis  of,  381 

pancreatic,  387 

phosphate,  383 

salivary,  388 

struvit,  383 

urate,  382 

uric  acid,  381,  388 

urinary,  380-386 

urostealith,  384 

xanthin,  384 
Cancerous  ascites,  412 
Cantharidin,  183 

Capillaries,  permeability  of,  280,  287 
Carbohydrates,  bacterial,  107 

fermentation  of,  479 
Carbolic  acid.     See  Phenol. 
gangrene,  307,  316 
poisoning,  473 
Carcinoma,  102,  299,  415,  467 

cachexia,  418,  458 

colloid,  426 

exudates  of,  418 

hemolysis  in,  418 

immunity  against,  419 

metabolism  in,  419 

of  mamma,  413 

onray,  314 

Cardiac  edema,  291,  349,  371,  514 
Caseation,  319-321 


Caseation,  autolysis  in,  97 
Casein,  bacterial,  106 
Castration  in  osteomalacia,  373 
Catalase,  70,  73,  74,  76,  233,  417 
Cataphoresis,  46 
Cataract,  535 

Cells,  chemistry  and  physics  of,  17- 
60 

plant,  37 

structure  of,  52-60 

wall,  composition  of,  58 
Cellulose,  107,  108 
Centipede  poison,  181 
Cephalin,  28 
Cerebrin,  231,  232 
Cestodes,  chemistry  of,  132-134 
Cetyl  alcohol,  424 
Chalicosis,  392 
Charcot's  crystals,  258 
Chemotactic  substances,  211-213 
Chemotaxis,  208-215,  262 

negative,  211,  217 

of  bacteria,  105 

of  lymphocytes,  213 
Chitin,  107,  129,  132,  135 
Chitosamin,  423 
Chlorides  in  edema,  293 
Chloroform  necrosis,  268 

poisoning,  98,  99,  445,  448,  457 
Chloroma,  399 
Chlorophyll,  127,  402 
Chlorosis,  250-252 
Cholemia,  407,  408 
Cholera,  476 

agglutinin,  140 

hemolysin,  140 

vibrios,  106,  108,  110,  114,  124 
Cholesteatoma,  346 

Cholesterin,  28,  38,  58,  107,  108,  157, 
183,  190,  195,  197,  231,  232,  234, 
235,  239,  245,  250,  253,  300,  301, 
320,  344,  346,  376-380,  399,  422, 
425,  427 

calculi,  376-380,  385 

pathological  occurrence,  346,  347 
Cholin,  97,  112,  118-120,  460,  480 
Chondrodystrophia  fcetalis,  493 
Chondroid,  347 
Chondroitin,  348 
Chondroitin-sulphuric  acid,  347,  350, 

356,  386,  420,  421,  423 
Chondroma,  421 
Chondrosin,  348,  423 
Chromatin,  26,  53,  104 
Chromogen  groups,  394 

reaction,  499 
Chromophile  cells,  400 
Chyle,  composition  of,  303 
Chyliform  effusions,  303 
Chylous  effusions,  303,  304 
Circulation,  disturbances  of,  238-275 


540 


INDEX 


Cirrhosis,  457,  466,  482 
Cloudy  swelling,  329-331 
Coagulation  of  blood,  185,  243,  246, 

256,  263-269,  449 
in  disease,  267-269 
modification  of,  135,  265-268 

of  cell  proteids,   312.      See  Rigor 
mortis. 

of  colloids,  49 

necrosis,  318,  319 
Coagulins,  263,  264,  270,  318 
Coal  pigment,  392 
Cobra  poisoning,  174 
Cold,  effect  on  cells,  312 
Collagen,  354,  420 
Colloid  cancer,  426 

degeneration,  354-356 

of  goiters,  490 

of  thyroid,  486,  487 

precipitation  of,  49 

properties  of,  40-52 
Colloids,  146,  151,  154, 194,  312,  323, 

329,  271,  422,  423 
Coma,  diabetic,  452-454 
Complement   144-147,  176 

hemolytic,  193 
Complementoid,  146 
Concretions,  375-392.    See  CalMi. 
Copper,  159,  213,  376 
Corpora  amylacea,  386 
Crabs,  poisons  of,  185 
Creatin,  132,  459 
Cresol,  161,  469,  473 
Cretinism,  491-493 
Crotin,  166,  196 

Crystalloids,  properties  of,  30-40 
Cutaneous  concretions,  391 
Cyclamin,  198 
Cystein,  22,  164 
Cysticercus  pisiformis,  133 

tenuicollis,  133 
Cystin,  22,  477-479 

calculi,  384 
Cystinuria,  118,  478 
Cystitis,  383 

Cystoma,  proliferating,  422 
Cysts,  butter,  425 

dermoid,  424 

hydatid,  362 

milk,  425 

ovarian,  422-425 

soap,  425 

Cytoplasm,  55-58 
Cytotoxins,  187-206 

DABOIA  Kussellii,  177 
Deamidization,  507,  522 
Defense  against  autolysis,  89, 94,  97 
Degeneration,  fatty,  332-347 
Dehydration  in  defense,  164 
Demineralization,  419 


Dermal  glands,  poisons  of,  182 
Dermoid  cysts,  424 
Detoxication  by  thyroid,  484 
Deutero-albumose,  369,  447,  468 
Dextrose.     See  Glucose. 
Diabetes,  81,  306,  344,  516-536 

and  obesity,  534 

bronzed,  404,  536 

glycogen  in,  363 

insipidus,  536 

metabolism  in,  534 

pancreas  in,  532-534 

phlorhizin,  520-524 
Diabetic  coma,  452-454 
Diacetic  acid,  452 
Diamino-acids,  22 
Diamins,  476 
Diapedesis,  242 
Diastase,  71,  72,  233 
Diathesis,  uric  acid,  510 
Dibothriocephalus  latus,  133 
Diffusion,  35-40,  45,  48 
Di-methylamine,  117 
Diphtheria,  319 

antitoxin,  140 

toxin,  122 
Dracunculus,  135 

ECLAMPSIA,  269,  439-443 

lactic  acid  in,  439-443 

thyroid  in,  442 
Edema,  276-305 

cardiac,  291,  349,  371,  514 

causes  of,  284-294 

chlorides  in,  293 

ex  vacuo,  319 

fluids,  physical  chemistry  of,  297 

hereditary,  294 

inflammatory,  293 

neuropathic,  294 

osmotic  pressure  in,  281, 289,  290 

renal,  292 

sodium  chloride  in,  293 
Eel  serum,  185,  199 
Egg  albumen,  155 
Ehrlich's  theory,  123,  137-139 
Elastin,  349,  354 
Elastinase,  325 
Electric  shock,  315 
Electrical  conductivity,  310,  435,  436 
Electricity,  effect  on  cells,  315 
Electrolytes  of  blood,  240 

properties,  31-35 
Elimination  of  poisons,  58 
Ellagic  acid,  389 
Emboli  of  placental  cells,  441 
Embolism,  272 

Emphysernatous  gangrene,  326 
Emulsin,  71,  72,  74 
Endocomplement,  193,  199 
Endotheliolytic  serum,  204 


INDEX 


541 


Endotheliotoxin,  176,  203,  242 
Endotoxins,  101,  113,  114,  115,  124 
Enterokinase,  70,  322 
Enzymes,  61-103 

action  of,  65-69 

activation  of,  70 

and  toxins,  relation  of,  75 

bacteria],  108-115 

composition  of,  63-65 

effect  of  antiseptics  on,  62,  69 
of  light  on,  313 

general  properties  of,  61-76 

glycolytic,  70,  81,  526,  527 

in  metabolism,  68 

in  sputum,  94 

in  tumors,  416,  417 

inorganic,  65 

intracellular,  75-103 

of  Bacillus  coli,  95 
tuberculosis,  98 

of  staphylococcus,  93,  95 

of  streptococcus,  93,  95 

oxidizing,  161,  233,  300,  308,  311, 
394,  417,  446,  508,  510 

proteolytic,  85 

reducing,  80 

resemblance  to  complement,  146 
to  toxins,  121 

reversible  action  of,  65-69 

synthesis  by,  65-69 

toxicity  of,'  71-72 

uricolytic,  510 
Eosinophiles,  259 
Eosinophilia,  129,  303 
Epeira,  181 
Epilepsy,  120,  461 
Erepsin,  85,  89,  91,  466 
Erysipeloid,  185 

Erythrocytolysis.     See  Hemolysis. 
Ethereal  sulphates,  470 
Ethyl  mercaptan,  477 

sulphide,  477 
Ethylidendiamin,  476 
Euglobulin,  140,  155,  296,  412 
Exophthalmic  goiter,  493-496 
Exudates,  288 

and  transudates,  295-297 

autolysis  of,  94-96 

cancer,  418 

FAT,  bacterial,  107 
decomposition  of,  480 
embolism,  272,  344 
in  caseation,  320 
metabolism,  67,  340 
necrosis,  84,  321-324 
of  lipomas,  421 
physiological    formation    of,    332- 

ponceau,  336 
staining  of,  336 


Fatigue,  119,  459-461 

mental,  460 

toxin  of,  460 
Fatty  acids,  233,  234,  272,  321,  324, 

325,  342,  345,  385,  425 
pathological  occurrence,  345 
staining  of,  336,  346 

degeneration,  332,  335-339 

distinction  from  infiltration,  340 
lecithin  in,  339 
of  kidney,  336,  338 

infiltration.     See  Fatty  degeneration 
and  Fatty  metamorphosis. 

metamorphosis,  332-347 
Fermentation,  gastro-intestinal,    468- 

482 

Fermentoid,  75,  122 
Ferments,  109.     See  Enzymes. 
Fetal  tissues,  glycogen  in,  359 
Fetus  as  source  of  intoxication,  442 
Fever,  312 
Fibrin,  263 

calculi,  385 

ferment,  96,  172,  233,  263,  264 
thrombosis,  271 

formation,  263-265 
Fibrinogen,  231,  246,  250,  263,  268, 

299 

Fibrinolysis,  263,  272 
Fibroma,  chemistry  of,  420 
Fibromyoma,  cystic,  420,  421 
Filaria,  135,  285 
Fish,  poisonous,  184,  185 
Fixation  of  poisons,  158 
Flagella,  108 
Fluorides,  159 
Food  poisoning,  117 
Formic  acid,  182,  459 
Freezing-point  of  blood,  435 

of  effusions,  292,  297 
Frogs,  dermal  gland  poisons,  183 
Fuchsin  bodies,  Russell's,  354 
Fusible  calculi,  383 

GALL  stones,  376-380 
Gangrene,  117,  234,  325,  326,  472 

carbolic  acid,  307,  316 

emphysematous,  326 

of  lung,  95,  110,  325 

x-ray,  314 
Gastro-enteritis,  81 
Gastro-intestinal  auto-intoxication,  464 

putrefaction,  468-482 
Gelatin,  267, 473 
Gels,  41 

Generative  functions,  485,  500 
Gentisic  acid,  475 
Giant  cell  formation,  217,  225,  226 
Giantism,  493,  496 
Gila  monster,  177 
Glabrificin,  150 


542 


INDEX 


Globin,  239,  243 

Globulin,  25,  141,  147,  149,  159,  172, 
239,  297,  298,  412 

cell,  311 

of  muscle,  327 

of  thyroid,  486 
Gluconic  acid,  530 
Gluco-proteid,  27 
Glucosamin,  21,  107, 234,  356 
Glucose,  metabolism  of.    See  Diabetes. 
Glucosides,  hemolytic,  197 
Glutaminic  acid,  20 
Glutin-casein,  212 
Glyceric  aldehyde,  523 
Glycerine,  324,  524 
Glycerose,  524 
Glycocoll,  20,  212,  414,  437,  448,  509 

as  protective  substance,  163 
Glycogen,  29, 107,  129,  132,  135,  159, 
231,  232,  300,  358-363,  427,  517 

in  diabetes,  363 

in  leucocytes,  362 

in  parasites,  361 

in  tumors,  414 

properties  of,  358 

staining  of,  358,  359 
Glycogenesis,  defective,  528 
Glycogenic  center,  519 
Glycolysis,  81 

Glycolytic  enzymes,  70,  81, 526, 527 
Glyconucleoproteid,  106 
Glycoproteid,  27,  127 
Glycosamin,  530 
Glycosuria,  516-536 

adrenalin,  501,  525 

alimentary,  516-518 

nervous,  519 

pancreatic,  525-530 
Glycuronic  acid,  158,  470,  473,  530 

as  protecting  substance,  162 
Glycylglycin,  23 
Goiter,  chemistry  of,  488-491 

exophthalmic,  493-496 
Gout,  511-514 

metabolism  in,  512 
Gouty  deposits,  391 

tophi,  513 

Gram's  method  of  staining,  109 
Guanase,  88,  507 
Guanin,  504,  506,  513,  515 
Guinea  worm,  135 

HAPTOPHORE  group,  122, 123, 137 
Hay  fever,  169 

antitoxin,  169 
Heart,  brown  atrophy  of,  399,  404 

fatty  degeneration  of,  338 

hypertrophy  of,  236 
Heat,  adaptation  to,  311 

effect  on  cells,  311 

rigor,  311 


Heliotropism,  210 

Heloderma  suspectum,  177 

Helvellic  acid,  168,  198 

Hemagglutinin,  194 

Hematin,  239,  243,  401 

Hematoidin,  244,  325,  397,  398,  401, 

405 

Hematoma,  400 
Hematoporphyrin,  402 
Hematuria  neonatorum,  514 
Hemochromatosis,  404 
Hemochromogen,  239 
Hemofuscin,  403 
Hemoglobin,  239,  245,  275,  400 

infarcts,  198 
Hemoglobinuria,  196,  197,  200,  461 

paroxysmal,  201,  250 
Hemolysin,  cholera,  140 
Hemolysis,    110,   131,    168,   187-202, 
243,  250,  254,  271,275 

by  bacteria,  194-196 

by  serum,  190-194 

by  vegetable  poisons,  196-198 

by  venoms,  198,  199 

in  cancer,  418 

in  disease,  200,  201 

in  icterus,  406 

inhibition  of,  360 

mechanism  of,  188-190 

post  mortem,  195 
Hemolytic  poisons,  137,  164,  169,  176, 

180,   181,   182,  183,  186,  187-202, 

203, 462 

Hemophilia,  245-247 
Hemorrhage,  242-247.     See  Anemia, 

secondary. 

Hemorrhagic  infarct,  275 
Hemorrhagin,  176,  178,  204,  242 
Hemosiderin,  244,  275,  401,  404 
Heredity,  474,  478 
Heterolysis,  92,  275 
Hexone  bases,  22 
Hippuric  acid,  67, 163,  308 
Hirudin.  135,  267 
Histidin,  22,  96,  98 
Histon,  257,  349 

nucleinate,  413 
Historetention,  293 
Hodgkin's  disease,  259 
Homogentisic  acid,  79,  397,  474 
Hyalin,  353,  354 
Hyaline  degeneration,  319,  353 

substances,  232 

thrombi,  270,  313,  316 
Hydatid  cysts,  362 
Hydrobilirubin,  409 
Hydrocele  fluid,  301 
Hydrocephalus  fluid,  302 
Hydrochinon,  473,  474 
Hydrocyanic  acid  poisoning,  446 
Hydrogen  sulphid,  160,  325,  403,  447 


INDEX 


543 


Hydrophidia,  171, 177 
Hydropic  degeneration,  331 
Hydrothorax,  295,  299 
Hyperemia,  260-262 

active,  207,  260,  286 

passive,  260-262,  291 
Hyperglycemia,  519,  526,  532,  535 
Hypernephroma,  102,  414,  427 
Hypertrophy  of  heart,  236 
Hypophysis,  496-498 
Hypoxanthin,  505,  507,  508 

ICHTHYOTOXIN,  185 

Icterus,  269,  405-410 

hematogenous,  250 

hemolysis  in,  406 
Ileus,  481 
Imbibition,  44 
Immune  body,  145 
Immunity,  136-156 

against  bacterial  cells,  143-148 

enzymes,  112 
cancer,  419 
morphine,  157 

to  phytotoxins,  167 
Indican,  162,  471 
Indigo  calculi,  384 
Indol,  161,  470-473 
Indol-acetic  acid,  473 
Indol-propionic  acid,  470 
Indo-phenol  reaction,  161 
Indoxyl,  471 
Infantilism,  493 
Infarction,  273-275 
Infarcts,  autolysis  in,  92,  93,  273 

glycogen  in,  360 

hemoglobin,  198 

hemorrhagic,  275 

uric-acid,  382,  514 
Inflammation,  207-237 

leucocytes  in,  224-226 
Inflammatory  edema,  293 
Inorganic  constituents  of  tumors,  415, 
416 

enzymes,  65 

poisons,  defense  against,  159 

substances,  235 
Inosite,  132,  536 
Insanity,  500 

Intercellular  substance,  60 
Intermediary  body,  145 
Intestinal  concretions,  388,  389 

intoxication,  446 

obstruction,  480 

occlusion,  481 

putrefaction,  410 

sand,  389 

Intoxication,  intestinal,  446 
Invertase,  71,  110,  417 
lodin,  213,  497 

in  tumors,  417 


lodipin,  335 

Iodized  proteids,  487 

lodophilia,  362 

lodothyrein,  486 

lonization,  31-35,  310,  315 

lon-proteids,  29,  58,  240,  315,  368 

Ions,  31-35 

Iron,  245,  253,  376,  401 

in  calcification,  365 

in  tumors,  416 

metabolism  of,  252 

sulphide,  403 
Iso-amylamin,  118 
Isocetinic  acid,  108 
Isohemolysins,  192 
Isoprecipitins,  153 
Isotonicity  of  corpuscles,  251,  253 

JAUNDICE.     See  Icterus. 
Jecorin,  29,  98,  232,  240,  519 

KARYOKINESIS,  237 

Karyolysis,  100,  309 

Karyorrhexis,  274,  309 

Kidney,  fatty  degeneration,  336,  338 

internal  secretion,  437 
Kinases,  70 

Knife-grinder's  lung,  392 
Krait,  177 
Kynurenic  acid,  470 

LACCASE,  79,  80 

Lactic  acid,  211,  231,  233,  249,  371, 

436,  447,  456,  459,  479,  523 
in  eclampsia,  439-443 
Lactose,  517 
Lactosuria,  518 
Lanthanin,  53 
Laurie  acid,  108 
Lead,  159 

Lecithin,  27,  28,  38, 58, 88,  94,  97,  107, 
118,  120,  146,  190,  193,  196,  197, 
216,  231,  232,  234,  239,  250,  253, 
299,  304,  320,  339,  366,  427,  448, 
480 

in  fatty  degeneration,  339 
Leech  extract,  278 
Leucin,  20,  95,  96,  98,  101,  112,  113, 

117,  212,  232,  236,  299,  325,  414, 

427,  447-450,  478,  522 
Leucocytes,  chemotaxis  of,  210 

composition  of,  239 

glycogen  in,  362 

in  autolysis,  91,  94,  95 

in  inflammation,  224-226 
Leucocytolysis,  190,  203 
Leucocytolytic  serum,  203 
Leucocytotoxin,  176,  203,  258 
Leukemia,  255-260 

autolysis  in,  101 
Levulose,  517,  518,  519,  524,  528 


544 


INDEX 


Levulosuria,  518 
Light,  effect  on  cells,  313 
Lightning,  315 
Linin,  53 

Lipase,  66-68,  71,  72,  74,  82-84,  113, 
132,  231,  233,  372,  275,  296,  300, 
322,  340-343,  417 

in  pus,  83 

Lipemia,  83,  344, 345,  533 
Lipochrome,  108,  128,  399 
Lipocyanin,  128,  399 
Lipoids,  27-29,  58,  59,  317,  339 
Lipoma,  421 

Liquefaction  necrosis,  319 
Liquid  air,  312 
Lithemia,  510 
Lithofellic  acid,  389 
Liver,  acute  yellow  atrophy  of,  443- 

450 
Lung,  gangrene  of,  95,  110 

knife-grinder's,  392 

stones,  390 
Lutein,  399 
Lymph,  absorption  of,  283 

composition  of,  276 

formation  of,  277 
Lymphagogues,  278 
Lymphatics,  obstruction  of,  285 
Lymphatolytic  serum,  204 
Lymphocytes,  chemotaxis  of,  213 
Lymphosarcorna,  412 
Lysin,  21,  96,  98,  101,  118,  449,  476 
Lysol,  158,  473 

MAGNESIUM,  372 

soaps,  425 
Malaria,  131,  200 
Malarial  pigmentation,  398 
Malic  acid,  208 
Malmignatte,  180 
Maltase,  66,  447,  517 
Manganese,  376 
Marasmus,  457 
Margarin,  325,  345 
Meat,  ripening  of,  99 
Mechanical  affinity,  45 

stimuli,  317 
Melanic  acid,  395 
Melanin,  79,  393-399 

in  Addison's  disease,  397 
Melanogen,  395 
Melanoid,  394 
Melanosarcoma,  396 
Melanotic  tumors,  396 
Melanuria,  395 
Membranes,  semipermeable,  36, 38,  59, 

Meningeal  effusions,  301 
Mental  fatigue,  460 
Mercaptan,  112 
Mercury,  159,  213,  221,  376 


Metabolism,  249,  251,  254,  257,  259, 
493,  497,  498,  499 

calcium,  497 

effect  of  thyroid  on,  483 

enzymes  in,  68 

in  cancer,  419 

in  diabetes,  534 

in  gout,  512 

nitrogenous,  437 

of  fat,  67,  340 
.  of  iron,  252 

of  uric  acid,  503-511 

relation  to  autolysis,  88 

rhythmical,  91 

x-rays  and,  314 
Metalbumin,  422,  423 
Metamorphosis  of  calculi,  381 
Metaplasia,  237 
Metastatic  calcification,  367 
Methane,  160,  163 
Methemoglobin,  245,  403 
Methyl  amine,  117 

mercaptan,  477 
Methylation,  160,  163 
Milk  cysts,  425 

Morphine,  immunity  against,  157 
Mucin,  107,  234,  355,  356,  357,  422, 

492 

Mucoid  degeneration  356-358 
Mucoids,  422-425 
Multiple  sclerosis,  345 
Muscarin,  118-120,  168,  480 
Mushroom  poisons,  168 
Myelin,  329,  339 
Myeloma,  256 

multiple,  427-430 
Myelopathic  albumosuria,  427-430 
Myelotoxic  serum,  204 
Myocarditis,  236,  501 
Myogen,  328 
Myosin,  327 
Myosinogen,  327 
Myristic  acid,  424 
Myristinic  acid,  108 
My  rosin,  71 

Myxedema,  357,  442,  491-493,  497 
Myxoma,  357 
Myxosarcoma,  426 

NAPHTHALIN,  162 
Naphthol,  162 
Necrobiosis,  308 
Necrosis,  307-326 

autolysis  in.  96 

chloroform,  268 

coagulation,  318,  319.     See  Casea- 
tion. 

fat,  321-324 

liquefaction,  319 

thermic,  311 
Nematodes,  134 


INDEX 


545 


Nephritis,  201,  205,  241,  268, 292,  293, 
295,  297,  300,  514 

Nephrolytic  serum,  204 

Nervous  glycosuria,  519 

tissue,  degeneration  of,  97,  118,  120, 
319,  338,  345,  460 

Neurasthenia,  472 

Neurin,  118-120,  460,  480 

Neurolytic  serum,  205 

Neuropathic  edema,  294 

Neurotoxic  substances,  463 

Neurotoxin,  176,  186,  205 

Neutralization  of  acids,  164 

Nitrogenous  metabolism,  437 

Nuclease,  88,  96,  274,  309,  507 

Nucleic  acid,  26,  237,  274,  506 

Nuclein  bodies,  504 

Nucleo-albumin,  27 

Nucleo-gluco-proteids,  26 

Nucleo-histon,  413 

Nucleoli,  composition  of,  54 

Nucleoproteid,  25-27,  106,  114,  126, 
154,  157,  159,203,  205,  231,  232, 
234,  236,  239,  252,  257,  270,  299, 
309,  381,  412,  486,  506,  514 
autolysis  of,  88 

Nucleus,  composition  of,  53-55 

OATMEAL  concretions,  389 

Obesity  and  diabetes,  534 

Ochronosis,  397 

Oleic  acid,  108,  336,  343 

Ophiotoxin,  172 

Opsonin,  147,  217 

Organic     poisons,     defense     against, 

160-165 

Ornithin,  118,  476 
Osmic  acid,  336 
Osmosis,  35-40 

Traube's  theory  of,  40 
Osmotic  pressure,  146,  330,  416,  435, 

438,  535 

effect  on  cells,  318 
in  edema,  281,  290 
Ossification,  364,  365 
Osteoid  tissue,  372 
Osteomalacia,  371-373,  374,  429 

castration  in,  373 
Osteomyelitis,  112 

Ovarian  cysts,  chemistry  of,  422-425 
Oxalate  calculi,  382,  387 
Oxalic  acid,  161,  383,  479,  508,  509 
Oxaluria,  479 
Oxidase,  63,  78,  507 
Oxidation  as  means  of  defense,  161 
Oxidizing  enzymes,  75-81,  161,  233, 

300,  308,  311,  394, 417, 446,  508,  510 
Oxygenase,  78 
Oxymandelic  acid,  447 
Qxy-prolin,  21 
Qxyuris  vermicularis,  135 

35 


PANCREAS  activator,  528 

in  diabetes,  532,  533 

internal  secretion  of,  527 

self-digestion,  324 
Pancreatic  calculi,  387 

glycosuria,  525-530 
Papain,  72 
Papayotin,  212 
Parabanic  acid,  509 
Parachromatin,  53 
Paracresol,  469 
Parahemoglobin,  245,  401 
Paralactic  acid.     See  Lactic  Add, 
Paralbumin,  422,  423 
Paralinin,  53 
Paramucin,  356, 423 
Paramyosinogen,  327 
Para-oxyphenyl-acetic  acid,  469, 473 
Para-oxyphenyl-propionic    acid,    469, 

473 

Parasites,  glycogen  in,  361 
Parathyroids,  487,  495 
Parenchvmatous    degeneration,    329- 

331 

Paresis,  461 
Parrot  fish,  184 
Pentose,  26,  102,  106,  449,  517 

in  tumors,  415 
Pentosuria,  518 

Pepsin,  67,  70,  71,  74,  114,  417,  465 
Peptone,  96,  97,   101,   105,   115,  153, 
212,  213,  231,  232,  234,  235,  256, 
278,  325,  414, 467 

toxicity  of,  466-468 
Peptotoxins,  463 
Peritonitis,  295,  298 
Peri  typhlitis,  99 
Permeability  of  cells,  310 
Pernicious  vomiting,  458 
Peroxidase,  78,  81,  417 
Phagocytosis,  208-229,  262 
Phallin,  169,  196 

Phenol,  158,  161,  398,  469,  471,  473 
Phenyl-alanin,  20,  469,  474 
Philocatalase,  77 
Phlogosin,  210 
Phloretin,  520 

Phlorhizin  diabetes,  520-524 
Phloridzin,  212.     See  Phlorhizin. 
Phosphate  calculi,  383 
Phospho-proteid,  27 
Phosphoric  acid  in  calcification,  370 
Phosphorus,  Kit) 

poisoning,  77,  80,   81,   83,   84,   98, 
264,  268,  335,  338,  345,  444-449 
Physical  agents,  effects  on  cells,  317 

chemistry  of  edema  fluids,  297 
Phyto-precipitins,  154 
Phytotoxins,  166-170,  196 
Pigmentation,  393-410 

malarial,  398 


546 


INDEX 


Pigments,  bacterial,  127 

hematogenous,  400-405 
Piperazin,  259 
Piperidine,  525 
Placenta,  retention  of,  458 

toxicity  of,  441 
Placental  cells,  emboli  of,  441 
Plaques.     See  Blood-platelets. 
Plasma,  composition,  of,  239 
Plasmase,  263 
Plasmodium,  208 

malarise,  131 
Plasmolysis,  105 
Plasmoptysis,  39,  105 
Plasmorrhexis,  39 
Plastein,  89,  103 
Plastin,  53 
Pleural  effusions,  363 
Pleurisy,  295,  298,  299,  301 
Pleuritic  exudate,  429 
Pneumobacillus,  212 
Pneumococcus,  124,  269,  299 
Pneumonia,  234,  241,  267,  268,   270, 
293,  298,  336,  345,  361, 363,  467, 
511 

autolysis  in,  95 

unresolved,  96 
Pneumonokoniosis,  392 
Pneumothorax,  305 
Poisoning,  carbolic  acid,  473 

chloroform,  98,  99,  445,  448,  457 

cobra,  173 

food,  117 

hydrocyanic  acid,  446 

phosphorus,  77,  80,  81,  83,  84,  98, 
264,  268,  335,  338,  345,  444-449 

viper,  174 
Poisons,  defense  against,  157-165 

inorganic,  159 

organic,  160 

protoplasmic,  316 
Pollen,  169 
Polypeptids,  23,  467 
Polyuria,  chronic,  536 
Post  mortem  changes,  99,  268,  324, 366, 

400,  403,  500 
lymph  secretion,  278 
Potassium,  236,  302,  331,  425,  433 
Potocytosis,  279 
Precipitation  of  colloids,  49 
Precipitin,  133, 141,  152-156, 179,  300 

reaction,  429,  436,  467 
Precipitogen,  153 
Precipitoid,  154 
Pregnancy,  vomiting  of,  458 
Preputial  concretions,  389 
Proliferation,  235-237 
Prolin,  21 

Prostatic  concretions,  390 
Protagon,  28,  58,  59,  97,  98,  330,  339 
Protamin,  22,  23,  66,  126,  237 


Proteases,  85-103,  130,  172,  215,  230, 

233,  243,  308,  321,  417 
Proteids,  bacterial,  229 

Bence-Jones,  427-430 

chemistry  of,  19-27 

iodized,  487 

of  tumors,  412-414 

poisonous  bacterial,  125-127 

precipitins  for,  152-156 

putrefaction  of,  469-477 

pyogenic,  106,  125,  229 

synthesis  of,  66 

Proteolytic   enzymes,   85.      See   Pro- 
teases. 

Proteose,  101,  103,  115,  172,  212,  232, 
234,  256,  266,  267,  273,  299,  302, 
325,  352,  369,  414,  427,  437,  447, 
448,  467 

toxicity  of,  466-468 
Prothrombin,  263 
Protoplasm,  definition  of,  18 

structure  of,  50-52,  56 
Protoplasmic  poisons,  316 

streaming,  220 
Protozoa,  chemistry  of,  130 
Pseudochylous  effusions,  304 
Pseudoglobulin,  140,  296,  304 
Pseudoleukemia,  259 
Pseudomelanosis,  403 
Pseudomucin,  355,  356,  422,  423 
Pseudomyxoma  peritonei,  424 
Ptomains,  115-120,  325,  418,  463,  476 
Pulmonary  gangrene,  325 
Purin,  504 

bases,  106, 232, 233, 256, 257, 258, 299 

bodies,  504-515,  534 
Purpura  hsemorrhagica,  265 
Pus,  229-233 

autolysis  of,  94,  95 

catalase  in,  77 

composition  of,  230-233 

corpuscles,  composition  of,  231 

lipase  in,  83 

serum,  composition  _of,  231 
Putrefaction,    gastro-intestinal,    468- 

482 

Putrescin,  118,  476,  478 
Pycnosis,  96,  274,  309 
Pyin,  232 
Pyocyanase,  114 
Pyocyanin,  128 

Pyogenic  proteids,  106,  125,  229 
Pyridin,  160,  163,  429,  463 
Pyrimidin  bases,  506 
Pyrocatechin,  473,  499,  501 
Pyrrolidin  carboxylic  acid,  21 

QUILL  A  j  A,  197 

RADIUM,  69,  102, 171,  314 
Reaction  of  degeneration,  331 


INDEX 


'547 


Receptor  of  the  second  order,  149 

Receptors,  124,  137 

Reducing  enzymes,  80 

Reduction  of  poisons,  160 

Regeneration,  235-237 

Renal  edema,  292 

Rennin,  67,  71,  72,  74,  111,  113,  233, 

352,  417 

Retrogressive  processes,  307-363 
Reversible  action  of  enzymes,  65-69 
Rheumatism.  459 
Rheumatoid  arthritis,  459 
Rhinoliths,  390 
Rhythmical  metabolism,  91 
Ricin,  166,  196 
Rickets,  373-375 
Rigor  mortis,  326-328 
Ripening  of  meat,  99 
Robin,  166,  196 
Rovida's  hyalin  substance,  232 
Russell's  fuchsin  bodies,  354 

SACCHARIC  acid,  530 
Salamander,  poisons  of,  182 
Salivary  calculi,  388 
Samandaridin,  183 
Samandarin,  183 
Sand,  intestinal,  389 
Saponin  157,  190,  197 
Sapotoxin,  197 
Sapremia,  325 
Sarcocystin,  131 
Sarcolactic  acid,  439,  455,  459 
Sarcoma,  102 
Sarcosporidia,  130,  131 
Scarlet  R,  336 
Scleroderma,  497 
Sclerosis,  multiple,  345 
Scorpion  poison,  179 
Secretin,  532 
Selenium,  160 
Self-digestion.     See  Autolysis. 

of  pancreas,  324 
Semipermeability  of  cell  membranes, 

317,  330 

Septicemia,  99,  293,  444 
Serin,  21,  523 
Serosamucin,  299 
Serum  albumin,  249,  250 

eel,  185,  199 

endotheliolytic,  204 

globulin,  249,  250,  253,  430 

hemolytic,  190-194 

leucocytolytic,  203 

lymphatolytic,  204 

myelotoxic,  204 

nephrolytic,  204 

neurolytic,  205  ^ 

of  pus,  composition  of,  231 

snake,  178 

thyrolytic,  205 


Serum,  toxicity  of,  142 

Sexual     development,     adrenals     in, 

500 

Shock,  electric,  315 
Skatol,  161,  212,  470,  473 

carboxylic  acid,  470 
Skatoxyl,  471 
Sialolithiasis,  388 
Siderosis,  392 
Silicates,  392 
Silver,  159 

Snake  venoms,  170-179,  270 
Snakes,  poisonous,  170 
Soap  cysts,  425 
Soaps,  321-324,  342,  425 
Sodium  chloride  in  edema,  293 

retention,  436 
Solanidin,  198 
Solanin,  198 
Sols,  41 

Solution  tension,  49 
Spermatocele  fluids,  301 
Spermin,  233,  259 
Spider  poison,  180 
Spina  bifida  fluid,  302 
Spores,  108 
Sputum,  233-235 

enzymes  in,  94 
Staining,  26,  53,  59,  308, 309 

of  amyloid,  350 

of  bacteria,  108 

of  fat,  336 

ot  fatty  acids,  336,  346 

of  glycogen,  358,  359 
Sta  phylococcus,  enzymes  of,  93,  95 

pvogenes,  108,  liO,  112,  113,  128, 
*194,    195,    202,    229,    232,    268, 
352 
Streptococcus,  112,  195,  268 

enzymes  of,  93,  95 
Struvh  calculi,  383 
Succinic  acid,  132 
Succus  entericus,  72 
Sudan  III,  336 
Sugar,  assimilation  limit  of,  517 

formation  from  fats,  523 
from  proteids,  522 

toxicity  of,  535 
Sulphemoglobin,  477 
Sulphide  of  iron,  403 
Sulphides,  160,  252 
Sulphur,  163 
Sulphuric  acid  as  protective  substance, 

161,471-473 

Sulphur-methemoglobin,  403 
Suppuration,  229-233,  269,  467 
Surface  tension,  40,  47,  150,  219 
Suspensions,  42 
Swelling,  cloudy,  329-331 
Syncytiolysins,  441 
Synthesis*  by  enzymes,  65-69 


548 


INDEX 


TABES  dorsalis,  120,  460 
Tactile  stimulation,  215 
Tsenia  echinococcus,  132 

marginata,  133 

saginata,  134 
Tarantula,  181 
Tellurium,  160,  163 
Tetanus  antitoxin,  140,  142 

toxin,  122,  123 
Tetany,  482,  484 
Tetrodon,  184 
Tetrodonic  acid,  185 
Tetrodonin,  185 

Theobald  Smith  phenomenon,  142 
Theobromine,  505 
Ihermic  necrosis,  311 
Thermotaxis,  214 
Thigmotaxis,  210 
Thrombi,  agglutination,  168,  194,  202 

biliary,  406 

calcined,  365 

formation  of,  269 

hyaline,  270,  313,  316 

softening  of,  271 
Thrombin,  263 
Thrombogen,  264 
Thrombokinase,  247,  264,  268 
Thrombosis,  262-272 

agglutinative,  168,  194,  202 
Thyreoglobulin,  486-487,  490 
Thyroid,  483-496 

colloid,  355 

effect  on  metabolism,  483 

in  eclampsia,  442 

tumors,  417 

Thyroidectomy,  effects  of,  492 
Thyroidismus,  493 
Thyroiodin,  355,  486,  487 
Thyrolytic  serum,  205 
Tissue  cells,  chemotaxis  of,  214,  226 
Toads,  poisons  of  dermal  glands,  182 
Tonsillar  concretions,  391 
Tophi,  gouty,  391,  513 
Toxalbumins,  166,  196 

bacterial,  106 
Toxicity  of  effusions,  300 
Toxin  of  fatigue,  460 
Toxins,  120-125 
Toxoid,  122,  137 
Toxones,  121 
Toxophore,  122,  123,  137 
Transudates  and  exudates,  295-297 

autolysis  in,  94,  95 
Traube's  theory  of  osmosis,  40 
Trichinella  spiralis  129,  135 
Trimethylamin,  117,  212 
Tropisms,  theory  of,  209 
Trypanosomes,  132 
Trypsin,  70,  71,  72,  73,  74,  114,  174, 

322,  324,  446,  465 
Tryptophan,  21,  414,  427,  469-472 


Tuberculin,  101, 126,  213,  468 

Tuberculosainin,  320 

Tuberculosis,  97,  102,  229,  232,  233, 

295,  298,   299,   302,   319-321,   360, 

363,  365,  390, 468 
Tumors,  autolysis  in,  101 

chemistry  of,  411-430 

enzymes  in,  416,  417 

glycogen  in,  361 

inorganic  constituents  of,  415,  416 

iodin  in,  417 

iron  in,  416 

melanotic,  396 

pentose  in,  415 

proteids  of,  412-414 

thyroid,  417 
Tungsten,  159 
Turgor,  37 

Tyndall's  phenomenon,  43 
Typhoid,  99,  268,  293 

agglutination,  140 
Typhus,  241 
Tyrosin,  21,  96,  98,  101, 112, 113,  212, 

"256,  299,  325,  395,  414,  427,  447- 

450,  469,  474,  478 
Tyrosinase,  70,  74,  79,  394,  398 
Tyrotoxicon,  481 

ULTRA-MICROSCOPIC  method,  43 
Uncinaria  duodenalis,  135 
Uranium,  524 
Urate  calculi,  382 

deposits,  513 

Urea,  163,  164,  212,  433,  508,  509 
Urease,  116 
Uremia,  241,  433-439 
Uric  acid,   161,   257,    299,   391,   447 
503-515 

calculi,  381,  388 

diathesis,  510 

infarcts,  382,  514 

metabolism  of,  503-511 
Uricolytic  enzymes,  510 
Urinary  calculi,  380-386 
Urine,  toxicity  of,  433 
Urobilin,  244,  250,  254,  382,  401,  409 
Urochrome,  382 
Uroerythrin,  382 
Uroleucic  acid,  474 
Uromelanin,  382 
Urosteaolith  calculi,  384 
Urticaria,  287,  294 
Uschinsky's  medium,  106 

VEGETABLE  poisons.     See  Phytotoxins. 
Venom.     See  Zootoxins. 

properties  of,  171 
Viper  poisoning,  174 
Viscosity  of  blood,  240,  262 
Vomiting  of  pregnancy,  458 

pernicious,  458 


INDEX 


549 


WAXY  degeneration,  330 
Welch's  hypothesis,  111,  143 
Wound  secretions,  302 

XANTHELASMA  multiplex,  400 
Xanthin,  504,  507 

bases.     See  Purin  bases 

bodies,  504 

calculi,  384 
ar-ray,  69, 101,  102,  258 


.r-ray,  effects  on  cells,  314 

gangrene,  314 

metabolism  and,  314 
Xylose,  415 

ZENKER'S  degeneration,  3 
Zooprecipitins,  154 
Zootoxins,  170-186 
Zymogens,  70,  91 
Zymophore,  122,  145 


SAUNDERS'  BOOKS 

OH      

Nervous  and  Mental 
Diseases,  Children, 
Hygiene,  Nursing,  and 
Medical  Jurisprudence 

W.  B.  SAUNDERS   COMPANY 

9,  HENRIETTA  ST.  COVENT  GARDEN,  LONDON 

925  WALNUT  STREET  PHILADELPHIA 

THE  SUPERIORITY  OF  SAUNDERS'  TEXT-BOOK 

In  a  recent  series  of  articles  entitled 

"WHAT  ARE  THE  BEST  MEDICAL  TEXT-BOOKS?" 

a  well  known  medical  journal  compiled  a  tabulation  of  the 
text-books  recommended  in  those  schools  which  are  members 
of  the  American  Association  of  Medical  Colleges.  The  text- 
books were  divided  into  twenty  (20)  subjects  and  under  each 
subject  was  given  a  list  of  the  various  books  with  the  number 
of  times  each  book  is  recommended.  Saunders'  books  head 
ten  (10)  of  the  twenty  (20)  subjects,  the  largest  number  head- 
ed by  any  other  publisher  being  three  (3).  In  other  words, 
Saunders'  books  lead  in  as  many  subjects  as  the  books  of  all  the  other 
publishers  combined. 

A  Complete  Catalogue  of  Our  Publications  will  he  Sent  upon  request 


SAUNDERS*    BOOKS   ON 


Peterson  and  Haines' 
Legal  Medicine  #  Toxicology 


A  Text-Book  of  Legal  Medicine  and  Toxicology.  Edited  by 
FREDERICK  PETERSON,  M.  D.,  Clinical  Professor  of  Pyschiatry,  College 
of  Physicians  and  Surgeons,  New  York;  and  WALTER  S.  HAINES, 
M.  D.,  Professor  of  Chemistry,  Pharmacy,  and  Toxicology,  Rush 
Medical  College,  in  affiliation  with  the  University  of  Chicago.  Two 
imperial  octavo  volumes  of  about  750  pages  each,  fully  illustrated. 
Per  volume:  Beautifully  bound  in  cloth,  2 is.  net. 

IN  TWO  VOLUMES-BOTH  VOLUMES  JUST  READY 

The  object  of  the  present  work  is  to  give  to  the  medical  and  legal  professions 
a  comprehensive  survey  of  forensic  medicine  and  toxicology  in  moderate  compass. 
This,  it  is  believed,  has  not  been  done  in  any  other  recent  work  in  English.  Under 
"  Expert  Evidence  "  not  only  is  advice  given  to  medical  experts,  but  suggestions 
are  also  made  to  attorneys  as  to  the  best  methods  of  obtaining  the  desired  infor- 
mation from  the  witness.  An  interesting  and  important  chapter  is  that  on  ' '  The 
Destruction  and  Attempted  Destruction  of  the  Human  Body  by  Fire  and  Chemi- 
cals." A  chapter  not  usually  found  in  works  on  legal  medicine  is  that  on  "  The 
Medicolegal  Relations  of  the  X-Rays."  This  section  will  be  found  of  unusual  im- 
portance. The  responsibility  of  pharmacists  in  the  compounding  of  prescriptions, 
in  the  selling  of  poisons,  in  substituting  drugs  other  than  those  prescribed,  etc. , 
furnishes  a  chapter  of  the  greatest  interest  to  every  one  concerned  with  questions 
of  medical  jurisprudence. 


OPINIONS  OF  THE  MEDICAL  PRESS 


Medical  News,  New  York 

"  It  not  only  fills  a  need  from  the  standpoint  of  timeliness,  but  it  also  sets  a  standard  01 
what  a  text-book  on  Legal  Medicine  and  Toxicology  should  be." 

Columbia  Law  Review 

"  For  practitioners  in  criminal  law  and  for  those  in  medicine  who  are  called  upon  to  give 
court  testimony  in  all  its  various  forms  ...  it  is  extremely  valuable." 

Pennsylvania  Medical  Journal 

"  If  the  excellence  of  this  volume  is  equaled  by  the  second,  the  work  will  easily  take  rank 
as  the  standard  text-book  on  Legal  Medicine  and  Toxicology." 


NERVOUS  AND  MENTAL   DISEASES. 


Church  and  Peterson's 
Nervous  anc  Mental  Diseases 


Nervous  and  Mental  Diseases.  By  ARCHIBALD  CHURCH,  M.  D., 
Professor  of  Nervous  and  Mental  Diseases  and  Head  of  Neurologic 
Department,  Northwestern  University  Medical  School,  Chicago ;  and 
FREDERICK  PETERSON,  M.  D.,  President  New  York  State  Commission 
on  Lunacy;  Clinical  Professor  of  Psychiatry,  College  of  Physicians 
and  Surgeons,  N.  Y.  Handsome  octavo,  922  pages ;  338  illustrations. 
Cloth,  2 is.  net 

FOURTH  EDITION.  THOROUGHLY  REVISED-RECENTLY  ISSUED 

This  work  has  met  with  a  most  favorable  reception  from  the  profession  at 
large,  four  editions  having  been  called  for  in  as  many  years.  It  fills  a  distinct 
want  in  medical  literature,  and  is  unique  in  that  it  furnishes  in  one  volume  prac- 
tical treatises  on  the  two  great  subjects  of  Neurology  and  Psychiatry.  In  this 
edition  the  book  has  been  thoroughly  revised  in  every  part,  both  by  additions  to 
the  subject  matter  and  by  rearrangement  wherever  necessary.  The  subjects  of 
Intermittent  Limping  and  Herpes  Zoster  have  been  given  a  section  each.  That 
form  of  epilepsy  marked  by  myoclonus,  furnishing  the  so-called  Combination 
Disease,  has  also  been  discussed.  Another  important  addition  is  a  new  section 
consisting  of  a  critical  review  of  psychiatry  from  the  German  viewpoint. 


OPINIONS  OF  THE   MEDICAL  PRESS 


Quarterly  Medical  Journal,  Sheffield,  England 

"  As  regards  this  edition,  it  is  only  necessary  to  add,  that  by  the  revision  and  additions 
which  the  authors  have  made,  the  work  has  been  still  further  improved  and  brought  thoroughly 
up  to  date." 

American  Journal  of  the  Medical  Sciences 

"  This  edition  has  been  revised,  new  illustrations  added,  and  some  new  matter,  and  really 
is  two  books.  .  .  .  The  descriptions  of  disease  are  clear,  directions  as  to  treatment  definite, 
and  disputed  matters  and  theories  are  omitted.  Altogether  it  is  a  most  useful  text-book." 

Journal  of  Nervous  and  Mental  Diseases 

"The  best  text-book  exposition  of  this  subject  of  our  day  for  the  busy  practitioner.  .  .  . 
The  chapter  on  idiocy  and  imbecility  is  undoubtedly  the  best  that  has  been  given  us  in  any 
work  of  recent  date  upon  mental  diseases.  The  photographic  illustrations  of  this  part  of  Dr. 
Peterson's  work  leave  nothing  to  be  desired." 


SAUNDERS*    BOOKS    ON 


Friihwald  and  WestcottV 
Diseases    of  Children 


Diseases  of  Children.  A  Practical  Reference  Book  for  Students 
and  Practitioners.  By  PROFESSOR  DR.  FERDINAND  FRUHWALD,  of 
Vienna.  Edited,  with  additions,  by  THOMPSON  S  WESTCOTT,  M.  D., 
Associate  in  Diseases  of  Children,  University  of  Pennsylvania.  Octavo 
volume  of  533  pages,  containing  176  illustrations.  Cloth,  i8s.  net. 

JUST   READY 

This  work  represents  the  author's  twenty  years'  experience,  and  is  intended 
as  a  practical  reference  work  for  the  student  and  practitioner.  With  this  refer- 
ence feature  in  view,  the  individual  diseases  have  been  arranged  alphabetically. 
The  prophylactic,  therapeutic,  and  dietetic  treatments  are  elaborately  discussed. 
The  practical  value  of  the  book  has  been  considerably  enhanced  by  the  many 
excellent  illustrations. 
E.  H.  Hartley,  M.  D., 

Professor  of  Pediatrics,  Chemistry,  and  Toxicology,  Long  Island  College  Hospital,  New  York. 
"It  is  a  new  idea,  which  ought  to  become  popular  because  of  the  alphabetic  arrangement. 
Its  title  expresses  just  what  it  is — a  ready  reference  hand-book." 


RuhrahV 
Diseases  of  Children 


A  Manual  of  Diseases  of  Children.  By  JOHN  RUHRAH,  M.  D., 
Clinical  Professor  of  Diseases  of  Children,  College  of  Physicians  and 
Surgeons,  Baltimore.  I2mo  of  404  pages,  fully  illustrated.  Flexible 
leather,  los.  net. 

JUST  READY 

In  writing  this  manual  Dr.  Ruhrah's  aim  was  to  present  a  work  that  would  be 
of  the  greatest  value  to  students.  All  the  important  facts  are  given  concisely  and 
explicitly,  the  therapeutics  of  infancy  and  childhood  being  outlined  very  care- 
fully and  clearly.  There  are  also  directions  for  dosage  and  prescribing,  and  a 
number  of  useful  prescriptions  are  included.  The  feeding  of  infants  is  given  in 
detail,  and  the  entire  work  is  amply  illustrated  with  practical  illustrations.  A 
valuable  aid  consists  in  the  many  references  to  pediatric  literature,  so  selected 
as  to  be  easily  accessible  by  the  student. 


INSANITY. 


Brower  and  Bannister 
on  Insanity 

A  Practical  Manual  of  Insanity.  By  DANIEL  R.  BROWER,  A.  M., 
M.  D.,  LL.  D.,  Professor  of  Nervous  and  Mental  Diseases  in  Rush 
Medical  College ;  and  HENRY  M.  BANNISTER,  A.  M.,  M.  D.,  formerly 
Senior  Assistant  Physician,  Illinois  Eastern  Hospital  for  Insane. 
Octavo  of  426  pages,  illustrated.  Cloth,  133.  net 

This  work  is  an  intelligible,  up-to-date  exposition  of  the  leading  facts  of  psy- 
chiatry, and  will  be  found  of  invaluable  service.  Certain  special  features  are  the 
mention  of  the  forms  of  insanity  not  usually  met  with  in  hospitals,  and  th*;  in- 
cluding of  a  comparative  table  of  classification  and  a  chapter  on  some  of  the 
ethical  questions  relating  to  insanity  as  they  may  arise  in  the  practice  of  medicine. 

Scottish  Medical  and  Surgical  Journal 

"  One  of  the  features  of  the  work  is  the  mention  that  is  made  of  the  various  physical  symp- 
toms of  insanity.  .  .  .  The  book  is  also  up  to  date  in  recording  advances  in  knowledge  and 
treatment." 

Abbott's  Transmissible   Diseases 

The  Hygiene  of  Transmissible  Diseases.  Their  Causation,  Modes 
of  Dissemination,  and  Methods  of  Prevention.  By  A.  C.  ABBOTT,  M.  D., 
Professor  of  Hygiene  and  Bacteriology,  University  of  Pennsylvania. 
Octavo,  311  pages,  with  numerous  illustrations.  Cloth,  95.  net. 

It  is  not  the  purpose  of  this  work  to  present  the  subject  of  Hygiene  in  the  com- 
prehensive sense  ordinarily  implied  by  the  word,  but  rather  to  deal  directly  with  but 
a  section — viz.,  that  embracing  a  knowledge  of  the  preventable  specific  diseases. 

The  Lancet,  London 

"  We  heartly  commend  the  book  as  a  concise  and  trustworthy  guide  in  the  subject  with 
which  it  deals,  and  we  sincerely  congratulate  Professor  Abbott." 


Griffith's  Care  of  the  Baby 

The  Care  of  the  Baby.  By  J.  P.  CROZER  GRIFFITH,  M.  D.,  Clinical 
Professor  of  Diseases  of  Children,  University  of  Penn. ;  Physician  to  the 
Children's  Hospital,  Phila.  i2mo  of  436  pp.  Illustrated.  Cloth,  6s.  net. 

RECENTLY  ISSUED— NEW  (3d)  EDITION 

New  York  Medical  Journal 

"  We  are  confident  if  this  little  work  could  find  its  way  into  the  hands  of  every  trained 
nurse  and  of  every  mother,  infant  mortality  would  be  lessened  by  at  least  fifty  per  cent." 


SAUNDERS'    BOOKS   ON 


GET  j^  I  \  9  THE  NEW 

THE  BEST  LJOrlcinCi    S  STANDARD 

Illustrated   Dictionary 

Just  Issued-The  New  (4th)  Edition 


Dot-land's  Illustrated  Medical  Dictionary.  A  new  and  com- 
plete dictionary  of  the  terms  used  in  Medicine,  Surgery,  Dentistry, 
Pharmacy,  Chemistry,  and  kindred  branches;  with  over  100  new  and 
elaborate  tables  and  many  handsome  illustrations.  By  W.  A.  NEWMAN 
BORLAND,  M.  D.,  Editor  of  "  Borland's  Pocket  Medical  Bictionary." 
Large  octavo,  nearly  800  pages,  bound  in  full  flexible  leather.  Price, 
193.  net;  with  thumb  index,  2 is.  net. 

Gives  a  Maximum  Amount  of  Matter  in  a  Minimum  Space,  and  at  the  Lowest 

Possible  Cost 

WITH   2000  NEW  TERMS 

The  immediate  success  of  this  work  is  due  to  the  special  features  that  distin- 
guish it  from  other  books  of  its  kind.  It  gives  a  maximum  of  matter  in  a  mini- 
mum space  and  at  the  lowest  possible  cost.  Though  it  is  practically  unabridged, 
yet  by  the  use  of  thin  bible  paper  and  flexible  morocco  binding  it  is  only  I  % 
inches  thick.  The  result  is  a  truly  luxurious  specimen  of  book-making.  In  this 
new  edition  the  book  has  been  thoroughly  revised,  and  upward  of  two  thousand 
new  terms  that  have  appeared  in  recent  medical  literature  have  been  added,  thus 
bringing  the  book  absolutely  up  to  date.  The  book  contains  hundreds  of  terms 
not  to  be  found  in  any  other  dictionary,  over  100  original  tables,  and  many  hand- 
some illustrations,  a  number  in  colors. 


PERSONAL    OPINIONS 


Howard  A.  Kelly,  M.  D., 

Professor  of  Gynecology,  Johns  Hopkins  University,  Baltimore. 

"  Dr.  Borland's  dictionary  is  admirable.     It  is  so  well  gotten  up  and  of  such  convenient 
size.     No  errors  have  been  found  in  my  use  of  it." 

J.  Collins  Warren,  M.D.,  LL.D.,  F.R.C.S.  (Hon.) 

Professor  of  Surgery ',  Harvard  Medical  School. 

"  I  regard  it  as  a  valuable  aid  to  my  medical  literary  work.     It  is  very  complete  and  of 
convenient  size  to  handle  comfortably.     I  use  it  in  preference  to  any  other." 


HYGIENE  AND  SANITATION. 


BergeyV 
Principles  of  Hygiene 


The  Principles  of  Hygiene:  A  Practical  Manual  for  Students, 
Physicians,  and  Health  Officers.  By  D.  H.  BERGEY,  A.  M.,  M.  D., 
Assistant  Professor  of  Bacteriology  in  the  University  of  Pennsylvania. 
Octavo  volume  of  536  pages,  illustrated.  Cloth,  133.  net. 

RECENTLY  ISSUED— SECOND  REVISED  EDITION 

This  book  is  intended  to  meet  the  needs  of  students  of  medicine  in  the 
acquirement  of  a  knowledge  of  those  principles  upon  which  modern  hygienic 
practices  are  based,  and  to  aid  physicians  and  health  officers  in  familiarizing 
themselves  with  the  advances  made  in  hygiene  and  sanitation  in  recent  years. 
The  book  is  based  on  the  most  recent  discoveries,  and  represents  the  practical 
advances  made  in  the  science  of  hygiene  up  to  date.  Among  the  important  sub- 
jects considered  are  Ventilation,  Heating,  Water  and  Water  Supplies,  Disposal  of 
Sewage  and  Garbage,  Food  and  Diet,  Exercise,  Clothing,  Personal  Hygiene,  Indus- 
trial Hygiene,  School  Hygiene,  Military  and  Naval  Hygiene,  Habitations,  Vital 
Statistics,  Disinfection,  Quarantine,  etc.  The  idea  of  the  book  is  to  give  the 
reader  a  clear  idea  of  the  general  principles  of  this  broad  subject.  The  rapid 
strides  made  in  our  knowledge  of  the  entire  subject  has  rendered  a  very  thorough 
revision  necessary,  this  new  second  edition  being  much  enlarged. 


OPINIONS  OF  THE   MEDICAL  PRESS 


The  Lancet,  London 

"  Will  be  found  suitable  for  the  needs  of  medical  officers  of  health,  and  those  interested  in 
public  health,  engineering,  and  architecture." 

American  Medicine 

"  The  readers  of  Dr.  Bergey's  treatise  cannot  fail  to  be  impressed  with  its  strictly  up-to- 
date  character,  and  with  the  fresh  and  unhackneyed  manner  in  which  the  subject  is  handled." 

Buffalo  Medical  Journal 

"  It  will  be  found  of  value  to  the  practitioner  of  medicine  and  the  practical  sanitarian  ;  and 
students  of  architecture,  who  need  to  consider  problems  of  heating,  lighting, ventilation,  water 
supply,  and  sewage  disposal,  may  consult  it  with  profit." 


SAUNDERS'   BOOKS   ON 


Draper's  Legal  Medicine 

A  Text-Book  of  Legal  Medicine.  By  FRANK  WINTHROP  DRAPER, 
A.  M.,  M.  D.,  Professor  of  Legal  Medicine  in  Harvard  University,  Bos- 
ton ;  Medical  Examiner  of  the  County  of  Suffolk,  Massachusetts,  etc. 
Handsome  octavo  volume  of  573  pages,  fully  illus.  Cloth,  i8s.  net. 

A  NEW  WORK— RECENTLY  ISSUED 

The  subject  of  Legal  Medicine  is  one  of  great  importance,  especially  to  the 
general  practitioner,  for  it  is  to  him  that  calls  to  attend  cases  which  may  prove  to 
be  medicolegal  in  character  most  frequently  come.  The  medicolegal  field  includes 
not  only  deaths  of  a  homicidal  nature,  but  also  suits  at  law — the  fatal  railway  acci- 
dent, machinery  casualties,  and  the  like,  to  which  the  neighboring  physician  may 
be  called,  and  later,  perhaps,  summoned  to  court.  It  is  evident,  therefore,  that 
every  practitioner  should  be  thoroughly  versed  in  all  branches  of  medicolegal 
science.  This  volume,  although  prepared  as  a  help  to  medical  students,  will  be 
fonud  no  less  valuable  and  instructive  to  practitioners.  The  author  has  had 
twenty-six  years'  experience  as  Medical  Examiner  for  the  city  of  Boston,  his  in- 
vestigations comprising  nearly  eight  thousand  deaths  under  a  suspicion  of  violence. 

Hon.  Olin  Bryan,  LL.  B. 

Professor  of  Medical  Jurisprudence,    Baltimore  Medical  College 

"  A  careful  reading  of  Draper's  Legal  Medicine  convinces  me  of  the  excellent  character  of 
the  work.  It  is  comprehensive,  thorough,  and  must,  of  a  necessity,  prove  a  splendid  acquisition 
to  the  libraries  of  those  who  are  interested  in  medical  jurisprudence." 

Jakob  and  FisherV 

Nervous  System  and  its  Diseases 

Atlas  and   Epitome  of   the  Nervous    System    and  Its  Diseases. 

By  PROFESSOR  DR.  CHR.  JAKOB,  of  Erlangen.  From  the  Second  Revised 
German  Edition.  Edited,  with  additions,  by  EDWARD  D.  FISHER,  M.  D., 
Professor  of  Diseases  of  the  Nervous  System,  University  and  Bellevue 
Hospital  Medical  College,  New  York.  With  83  plates  and  copious  text. 
Cloth,  155.  net.  ///  Saunders'  Hand- Atlas  Series. 

The  matter  is  divided  into  Anatomy,  Pathology,  and  Description  of  Diseases 
of  the  Nervous  System.  The  plates  illustrate  these  divisions  most  completely  ; 
especially  is  this  so  in  regard  to  pathology.  The  exact  site  and  character  of  the 
lesion  are  portrayed  in  such  a  way  that  they  cannot  fail  to  impress  themselves  on 
the  memory  of  the  reader. 

Philadelphia  Medical  Journal 

"•We  know  of  no  one  work  of  anything  like  equal  size  which  covers  this  important  and 
complicated  field  with  the  clearness  and  scientific  fidelity  of  this  hand-atlas." 


PERSONAL   HYGIENE. 


Galbraith's 
Four  Epochs  of  Woman's  Life 

Second  Revised  Edition— Recently  Issued 


The  Four  Epochs  of  Woman's  Life:  A  Study  in  Hygiene.  By 
ANNA  M.  GALBRAITH,  M.  D.,  Fellow  of  the  New  York  Academy  of 
Medicine,  etc.  With  an  Introductory  Note  by  JOHN  H.  MUSSER,  M.D., 
Professor  of  Clinical  Medicine,  University  of  Pennsylvania.  I2mo 
volume  of  247  pages.  Cloth,  6s.  6d.  net. 

MAIDENHOOD,  MARRIAGE.  MATERNITY,  MENOPAUSE 

In  this  instructive  work  are  stated,  in  a  modest,  pleasing,  and  conclusive 
manner,  those  truths  of  which  every  woman  should  have  a  thorough  knowledge. 
Written,  as  it  is,  for  the  laity,  the  subject  is  discussed  in  language  readily  grasped 
even  by  those  most  unfamiliar  with  medical  subjects. 

Birmingham  Medical  Review,  England 

"  We  do  not  as  a  rule  care  for  medical  books  written  for  the  instruction  of  the  public.    But 
we  must  admit  that  the  advice  in  Dr.  Galbraith's  work  is  in  the  main  wise  and  wholesome." 

Pyle's  Personal  Hygiene 


A  Manual  of  Personal  Hygiene  :  Proper  Living  upon  a  Physiologic 
Basis.  By  Eminent  Specialists.  Edited  by  WALTER  L.  PYLE,  A.  M., 
M.  D.,  Assistant  Surgeon  to  Wills  Eye  Hospital,  Philadelphia.  Octavo 
volume  of  441  pages,  fully  illustrated.  Cloth,  6s.  net. 

NEW  (2d)  EDITION-RECENTLY  ISSUED 

The  object  of  this  manual  is  to  set  forth  plainly  the  best  means  of  developing 
and  maintaining  physical  and  mental  vigor.  It  represents  a  thorough  exposition 
of  living  upon  a  physiologic  basis.  In  this  new  second  edition  there  have  been 
added  new  chapters  on  Home  Gymnastics  and  Domestic  Hygiene,  besides  an 
Appendix  of  Emergency  Procedures. 

Boston  Medical  and  Surgical  Journal 

"  The  work  has  been  excellently  done,  there  is  no  undue  repetition,  and  the  writers  have 
succeeded  unusually  well  in  presenting  facts  of  practical  significance  based  on  sound  knowl- 
edge." 


SAUNDERS*  BOOKS  ON 


Friedenwald  &  Ruhrah's 
Dietetics  for  Nurses 


Dietetics  for  Nurses.  By  JULIUS  FRIEDENWALD,  M.  D.,  Clinical 
Professor  of  Diseases  of  the  Stomach,  College  of  Physicians  and  Sur- 
geons, Baltimore ;  and  JOHN  RUHRAH,  M.  D.,  Clinical  Professor  of 
Diseases  of  Children,  College  of  Physicians  and  Surgeons,  Baltimore. 
I2mo  of  363  pages.  Cloth,  6s.  6d.  net. 

JUST   ISSUED 

This  work  has  been  prepared  to  meet  the  needs  of  the  nurse,  both  in  the 
training  school  and  after  graduation.  It  aims  to  give  the  essentials  of  dietetics, 
considering  briefly  the  physiology  of  digestion  and  the  various  classes  of  foods 
and  the  part  they  play  in  nutrition.  The  subjects  of  infant  feeding  and  the  feeding 
of  the  sick  are  fully  discussed,  and  rectal  alimentation  and  the  feeding  of  oper- 
ative cases  are  fully  described.  Diet-lists  and  recipes  for  the  invalid's  dietary 
are  appended. 

Ed  in  burg  Medical  Journal 

"It   appears  to   us   to   contain   all  the   practical  side  of  dietetics,  of  handy  size  and  de- 
void of  padding." 


Lewis'   Anatomy  and 
Physiology  for  Nurses 

Anatomy  and  Physiology  for  Nurses.     By  LERov  LEWIS,  M.  D., 
Surgeon  to  and  Lecturer  on  Anatomy  and   Physiology  for  Nurses  at 
the  Lewis  Hospital,  Bay  City,  Michigan.     I2mo   of  317  pages,  with 
146  illustrations.     Cloth,  73.  6d.  net. 

JUST  ISSUED 

The  author  has  based  the  plan  and  scope  of  the  work  on  the  methods  he  has 
employed  in  teaching  the  subjects,  and  has  made  the  text  unusually  simple  and 
clear.  The  object  was  so  to  deal  with  anatomy  and  physiology  that  the  student 
might  easily  grasp  the  primary  principles,  at  the  same  time  laying  a  broad  foun- 
dation for  a  wider  study.  The  text  is  rendered  more  comprehensive  by  the 
practical  illustrations,  representing  the  best  that  could  be  obtained. 


DISEASES   OF   CHILDREN.  11 

Starr  and  Westcott  on 
Diseases  of  Children 

A  Text-Book  of  Diseases  of  Children.  Edited  by  Louis  STARR, 
M.  D.,  Consulting  Pediatrist  to  the  Maternity  Hospital,  etc. ;  assisted 
by  THOMPSON  S.  WESTCOTT,  M.  D.,  Attending  Physician  to  the  Dispen- 
sary for  Diseases  of  Children,  Hospital  of  the  University  of  Pennsylvania. 
Two  handsome  octavos,  1244  pages,  profusely  illustrated.  Beautifully 
bound  in  Cloth,  305.  net. 

SECOND   REVISED   EDITION 

To  keep  up  with  the  rapid  advances  in  the  field  of  pediatrics,  the  whole  sub- 
ject-matter embraced  in  the  first  edition  has  been  carefully  revised,  new  articles 
added,  some  original  papers  amended,  and  a  number  entirely  rewritten  and 
brought  up  to  date.  The  volume  has  thus  been  increased  in  size  by  a  very 
considerable  amount  of  fresh  material. 

British  Medical  Journal 

"  May  be  recommended  as  a  thoroughly  trustworthy  and  satisfactory  guide  to  the  subject 
of  the  diseases  of  children." 

Paul's  Fever  Nursing 


Nursing  in  the  Acute  Infectious  Fevers.  By  GEORGE  P.  PAUL, 
M.  D.,  Assistant  Visiting  Physician  and  Adjunct  Radiographer  to  the 
Samaritan  Hospital,  Troy,  N.  Y.  I2mo  volume  of  200  pages.  Cloth, 
45.  net. 

JUST   ISSUED 


Dr.  Paul  his  written  this  little  work  especially  for  the  trained  nurse,  so  that  all 
extraneous  matter  has  been  studiously  avoided.  The  author  has  laid  great  stress 
upon  care  and  management  in  each  disease,  as  this  relates  directly  to  the  duties 
of  the  nurse.  The  book  is  divided  into  three  parts.  The  first  part  treats  of  fever 
in  its  general  aspects  ;  the  second  discusses,  each  of  the  acute  infectious  fevers, 
giving  cause,  signs,  symptoms,  course,  prognosis,  care,  and  management ;  the 
third  deals  with  practical  procedures  and  information  necessary  to  the  proper 
management  of  the  diseases  discussed. 


12  SAUNDERS*    BOOKS   ON 

Hofmann  and  Peterson's 
Legal  Medicine 

Atlas  of  Legal  Medicine.  By  DR.  E.  VON  HOFMANN,  of  Vienna, 
Edited  by  FREDERICK  PETERSON,  M.  D.,  Clinical  Professor  of  Psychi- 
atry in  the  College  of  Physicians  and  Surgeons,  New  York.  With  1 20 
colored  figures  on  56  plates  and  193  half-tone  illustrations.  Cloth, 
153.  net.  In  Saunders'  Hand- Atlas  Series. 

By  reason  of  the  wealth  of  illustrations  and  the  fidelity  of  the  colored  plates, 
the  book  supplements  all  the  text-books  on  the  subject.  Moreover,  it  furnishes  to 
every  physician,  student,  and  lawyer  a  veritable  treasure-house  of  information. 

The  Practitioner,  London 

"  The  illustrations  appear  to  be  the  best  that  have  ever  been  published  in  connection  with 
this  department  of  medicine,  and  they  cannot  fail  to  be  useful  alike  to  the  medical  jurist  and  to 
the  student  of  forensic  medicine." 

Chapman's          > 
Medical  Jurisprudence 

Medical  Jurisprudence  and  Toxicology.  By  HENRY  C.  CHAPMAN, 
M.  D.,  Professor  of  Institutes  of  Medicine  and  Medical  Jurisprudence  in 
Jefferson  Medical  College,  Philadelphia.  I2mo  volume  of  329  pages, 
fully  illustrated.  Cloth,  8s.  net. 

RECENTLY  ISSUED-THIRD  REVISED  EDITION,  ENLARGED 

This  work  is  based  on  the  author's  practical  experience  as  coroner's  physician 
of  the  City  of  Philadelphia  for  a  period  of  six  years.  Dr.  Chapman's  book, 
therefore,  is  of  unusual  value.  This  third  edition  has  been  thoroughly  revised 
and  greatly  enlarged,  so  as  to  bring  it  absolutely  in  accord  with  the  very  latest 
advances  in  this  important  branch  of  medical  science.  There  is  no  doubt  it  will 
meet  with  as  great  favor  as  the  previous  editions. 

Medical  Record,  New  York 

"  The  manual  is  essentially  practical,  and  is  a  useful  guide  for  the  general  practitioner, 
besides  possessing  literary  merit." 


NURSING.  13 


Golebiewski  and  Bailey's 
Accident  Diseases 


Atlas  and  Epitome  of  Diseases  Caused  by  Accidents.     By  DR.  ED. 

GOLEBIEWSKI,  of  Berlin.  Edited,  with  additions,  by  PEARCE  BAILEY, 
M.D.,  Consulting  Neurologist  to  St.  Luke's  Hospital,  New  York. 
With  71  colored  figures  on  40  plates,  143  text-illustrations,  and 
549  pages  of  text.  Cloth,  i6s.  net.  In  Saunders*  Hand- Atlas 
Series. 

This  work  contains  a  full  and  scientific  treatment  of  the  subject  of  accident 
injury  ;  the  functional  disability  caused  thereby  ;  the  medicolegal  questions  in- 
volved, and  the  amount  of  indemnity  justified  in  given  cases.  The  work  is 
indispensable  to  every  physician  who  sees  cases  of  injury  due  to  accidents,  to 
advanced  students,  to  surgeons,  and,  on  account  of  its  illustrations  and  statistical 
data,  it  is  none  the  less  useful  to  accident-insurance  organizations. 

The  Medical  Record,  New  York 

"  This  volume  is  upon  an  important  and  only  recently  systematized  subject,  which  is  grow- 
ing in  extent  all  the  time.     The  pictorial  part  of  the  book  is  very  satisfactory." 

Stoney's 
Materia  Medica  for  Nurses 

Practical  Materia  Medica  for  Nurses,  with  an  Appendix  containing 
Poisons  and  their  Antidotes,  with  Poison-Emergencies  ;  Mineral  Waters  ; 
Weights  and  Measures ;  Dose-List,  and  a  Glossary  of  the  Terms  used 
in  Materia  Medica  and  Therapeutics.  By  EMILY  M.  A.  STONEY,  of  the 
Carney  Hospital,  South  Boston.  1 2mo  of  300 pages.  Cloth,  8s.  net. 

JUST    ISSUED— NEW  (3rd)  EDITION 

In  making  the  revision  for  this  new  third  edition,  all  the  newer  drugs  have 
been  introduced  and  fully  discussed.  The  consideration  of  the  drugs  includes 
their  sources  and  composition,  their  various  preparations,  physiologic  actions, 
directions  for  administering,  and  the  symptoms  and  treatment  of  poisoning. 

journal  of  the  American  Medical  Association 

"  So  far  as  we  can  see,  it  contains  everything  that  a  nurse  ought  to  know  in  regard  to  drugs. 
As  a  reference-book  for  nurses  it  will  without  question  be  very  useful." 


14  SAUNDERS*    BOOKS    ON 


Stoney's  Nursing 


Practical  Points  in  Nursing :  for  Nurses  in  Private  Practice.  By 
EMILY  M.  A.  STONEY,  Superintendent  of  the  Training  School  for  Nurses 
at  the  Carney  Hospital,  South  Boston,  Mass.  466  pages,  fully  illus- 
trated. Cloth,  75.  6d.  net. 

THIRD   EDITION,  THOROUGHLY  REVISED— RECENTLY   ISSUED 

In  this  volume  the  author  explains  the  entire  range  of  private  nursing  as  dis- 
tinguished from  hospital  nursing,  and  the  nurse  is  instructed  how  best  to  meet  the 
various  emergencies  of  medical  and  surgical  cases  when  distant  from  medical  or 
surgical  aid  or  when  thrown  on  her  own  resources.  An  especially  valuable  feature 
will  be  found  in  the  directions  how  to  improvise  everything  ordinarily  needed  in  the 
sick-room. 

The  Lancet,  London 

"A  very  complete  exposition  of  practical  nursing  in  its  various  branches,  including  obstetric 
and  gynecologic  nursing.  The  instructions  given  are  full  of  useful  detail." 


Stoney's  Technic  for  Nurses 

Bacteriology  and  Surgical  Technic  for  Nurses.  By  EMILY  M.  A. 
STONEY,  Superintendent  at  Carney  Hospital,  South  Boston.  Revised 
by  FREDERIC  R.  GRIFFITH,  M.  D.,  Surgeon,  of  New  York.  I2mo, 
278  pages,  illustrated.  Cloth,  6s.  6d.  net. 

RECENTLY  ISSUED— NEW  (2d)  EDITION 
Trained  Nurse  and  Hospital  Review 

"  These  subjects  are  treated  most  accurately  and  up  to  date,  without  the  superfluous  reading 
which  is  so  often  employed.  .  .  .  Nurses  will  find  this  book  of  the  greatest  value  both  during 
their  hospital  course  and  in  private  practice." 

Spratling  on  Epilepsy 

Epilepsy  and  Its  Treatment.     By  WILLIAM  P.  SPRATLING,  M.  D.r 
Medical  Superintendent  of  the  Craig  Colony  for  Epileptics,  Sonyea, 
New  York.     Octavo  of  522  pages',  fully  illustrated.     Cloth,  1 8s.  net. 
The  Lancet,  London 

"  Dr.  Spratling's  work  is  written  throughout  in  a  clear  and  readable  style.  .  .  .  The  work 
is  a  mine  of  information  on  the  whole  subject  of  epilepsy  and  its  treatment." 


NURSING.  15 


De  Lee's  Obstetrics  for  Nurses 

Obstetrics  for  Nurses.  By  JOSEPH  B.  DE  LEE,  M.D.,  Professor 
of  Obstetrics  in  the  Northwestern  University  Medical  School;  Lecturer 
in  the  Nurses'  Training  Schools  of  Mercy,  Wesley,  Provident,  Cook 
County,  and  Chicago  Lying-in  Hospitals.  I2mo  volume  of  460  pages, 

fully  illustrated.  Cloth,  I2s.  net. 

JUST  ISSUED     NEW  (2nd)  EDITION 

The  illustrations  in  Dr.  De  Lee's  work  are  nearly  all  original,  and  represent 
photographs  taken  from  actual  scenes.  The  text  is  the  result  of  the  author's  eight 
years'  experience  in  lecturing  to  the  nurses  of  five  different  training  schools. 

J.  Clifton  Edgar,  M.  D., 

Professor  of  Obstetrics  and  Clinical  Midwifery,  Cornell  Medical  School,  N.  Y. 
"  It  is  far-and-away  the  best  that  has  come  to  my  notice,  and  I  shall  take  great  pleasure  in 
recommending  it  to  my  nurses,  and  students  as  well."' 

Davis*  Obstetric  and 
Gynecologic  Nursing 

Obstetric  and  Gynecologic  Nursing.  By  EDWARD  P.  DAVIS,  A.M., 
M.  D.,  Professor  of  Obstetrics,  Jefferson  Medical  College  and  Philadel- 
phia Polyclinic.  I2mo  of  400  pages,  illustrated.  Buckram,  8s.  net. 

RECENTLY  ISSUED— SECOND  REVISED  EDITION 

The  Lancet,  London 

"  Not  only  nurses,  but  even  newly  qualified  medical  men,  would  learn  a  great  deal  by  a 
perusal  of  this  book.  It  is  written  in  a  clear  and  pleasant  style,  and  is  a  work  we  can  recom- 
mend." 

Reference  Handbook  for  Nurses 

A  Reference  Handbook  for  Nurses.  By  AMANDA  K.  BECK,  of 
Chicago,  111.  32mo  of  177  pages.  Flexible  morocco,  55.  net. 

RECENTLY  ISSUED 

This  little  book  contains  information  upon  every  question  that  comes  to  a 
nurse  in  her  daily  work,  and  embraces  all  the  information  that  she  requires  to 
carry  out  any  directions  given  by  the  physician. 

Boston  Medical  and  Surgical  Journal 

••Must  be  regarded  as  an  extremely  useful  book,  not  only  for  nurses,  but  for  physicians." 


1  6  SAUNDERS'   BOOKS   Off  CHILDREN. 


Borland's  Pocket  Dictionary 

BORLAND'S  POCKET  MEDICAL  DICTIONARY.  Edited  by  W.  A.  NEW- 
MAN BORLAND,  M.  D.,  Assistant  Obstetrician  to  the  Hospital  of  the 
University  of  Pennsylvania.  Containing  the  pronunciation  and  defini- 
tion of  the  principal  words  used  in  medicine  and  kindred  sciences,  with 
64  extensive  tables.  Handsomely  bound  in  flexible  leather,  with  gold 
edges,  55.  net  ;  with  patent  thumb  index,  6s.  net. 

"  I  can  recommend  it  to  our  students  without  reserve."  —  J.  H.  HOLLAND,  M.  D.,  Dean 
of  the  Jefferson  Medical  College,  Philadelphia. 

Morrow's  Immediate  Care  of  Injured  just  Ready 

IMMEDIATE  CARE  OF  THE  INJURED.  By  ALBERT  S.  MORROW,  M.  D., 
Attending  Surgeon  to  the  New  York  City  Hospital  for  the  Aged  and 
Infirm.  Octavo  of  350  pages,  with  250  illustrations. 

Dr.  Morrow's  book  on  emergency  procedures  is  written  in  a  definite  and  decisive  style, 
the  reader  being  told  just  what  to  do  in  every  emergency.  It  is  a  practical  book  for  every 
day  use,  and  the  large  number  of  excellent  illustrations  can  not  but  make  the  treatment  to 
be  pursued  in  any  case  clear  and  intelligible.  Physicians  and  nurses  will  find  it  indispensible. 

Crothers'  Morphinism 

MORPHINISM  AND  OTHER  NARCOMANIAS  :  their  Etiology,  Treatment, 
and  Medicolegal  Relations.  By  T.  D.  CROTHERS,  M.  D.,  Superin- 
tendent of  Walnut  Lodge  Hospital,  Hartford,  Conn.  i2mo  of  351 
pages.  Cloth,  95.  net. 

Grafstrom's  Mechano-Therapy 

A  TEXT-BOOK  OF  MECHANO-THERAPY  (Massage  and  Medical  Gymnas- 
tics). By  AXEL  V.  GRAFSTROM,  B.  Sc.,  M.  D.,  late  House  Physician, 
City  Hospital,  Blackwell's  Island,  New  York.  i2mo,  139  pages,  illus- 
trated. Cloth,  55.  net. 

Chapin's  Insanity 

A  COMPENDIUM  OF  INSANITY.  By  JOHN  B.  CHAPIN,  M.  D.,  LL.D., 
Physician-in-Chief,  Pennsylvania  Hospital  for  the  Insane  ;  Honorary 
Member  of  the  Medico-Psychological  Society  of  Great  Britain,  of  the 
Society  of  Mental  Medicine  of  Belgium,  etc.  i2mo,  234  pages,  illus- 
trated. Cloth,  53.  net. 

Starr's  Diets  for  Infants  and  Children 

DIETS  FOR  INFANTS  AND  CHILDREN  IN  HEALTH  AND  IN  DISEASE.  By 
Louis  STARR,  M.  D.,  editor  of  "A  Text-Book  of  the  Diseases  of  Chil- 
dren." 230  blanks  (pocket-book  size),  perforated  and  neatly  bound 
in  flexible  Cloth,  53.  net. 


